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A method is described for measuring 3-methoxy-4-hydroxyphenethylene glycol (MHPG) in plasma by gas—liquid chromatography with electron capture detection. Seventy-two percent of whole blood MHPG was found in the plasma and 28% in the particulate fraction. The plasma levels of total MHPG for control subjects was 15.7 ng ± 2.0 and 32.5% ± 4.4% of the total MHPG was found to be in the free form. Plasma levels of MHPG on three consecutive days for the same subjects showed minimal variation, although there was a substantial variation from subject to subject. The method is applicable for determining plasma MHPG levels in other species than humans.

In order to determine the cortical areas of representation for the laryngeal muscles inMacaca mulatta, the inferolateral motor portions of both hemispheres were electrically stimulated. Muscular responses were observed under α-chloralose anesthesia. Stimulation of areas on the cortical surface with monopolar eletrodes, by a 100/sec constant current, resulted in differentiated contractions of the thyroarytenoid, cricothyroid or extrinsic laryngeal muscles. Responses were observed visually and measured by force transducers attached to the dissected muscles. InMacaca mulatta, these areas lie primarily within von Bonin and Bailey's histologically designated area FCBm. In several experiments, heart rate was also monitored. At threshold stimulation values, heart rate changes occurred only from the area principally devoted to responses of the cricothyroid muscle. The results of this study are discussed in relation to the possible differential motor innervation by vagal and accessory nerve components of the recurrent laryngeal nerve.

Summary Visual suppression of vestibular nystagmus was studied in rhesus monkeys. In the presence of vision the velocity of slow phases of caloric nystagmus was reduced by about 50%. The percent reduction in slow phase velocity was independent of the intensity of the nystagmus except when the nystagmus was weak. Visual suppression was similar when tested several times on the same day but tended to increase if there was spontaneous nystagmus or if testing was done over a more prolonged period of time. Percent reduction of slow phase velocity of caloric nystagmus in light as compared with that in darkness would appear to be a convenient and stable method for assessing the strength of visual fixation. Visual fixation also suppressed spontaneous nystagmus and positional alcohol nystagmus (PAN). Higher levels of alcohol were shown to reduce or abolish visual suppression of PAN and of caloric nystagmus.

Experimental allergic encephalomyelitis was induced in Rhesus monkeys and a baboon following intradermal inoculation both with purified myelin basic protein and homologous central nerve tissue in Freund's complete adjuvant. Weight loss and neurologic signs of muscular weakness, ataxia, and ocular disturbances developed as early as 2 weeks following injection. Unlike rodent species, foci of gross necrosis were seen which localized predominantly in the brain stem and cerebellar white matter with occasional foci occurring in the cerebrum as well. Histologically the lesions consisted of perivascular infiltrates of mononuclear cells; in severely affected areas parenchymal infiltrates contained a substantial proportion of polymorphonuclear cells. Demyelination was coextensive with the area of inflammatory cells. Immunofluorescent studies revealed perivascular binding of gamma-globulin, albumin and complement components suggesting increased cerebrovascular permeability in affected monkeys.

To determine the metabolic role of carnitine in bovine epididvmal and rhesus (Macaca mulatta) ejaculated spermatozoa, we studied the effect ofubstrate utilization on the acylation state of carnitine and on the acetylation state of carnitine and CoA. The acetylcarnitine content of bovine spermatozoa incubated in fructose, glucose. pyruvate. lactate. acetoacetate. a-OH butyrate. and acetate was significantly higher than that of nonincubated cells or cells incubated without substrate. In bovine cells incubated with palmitate or without substrate, however, the levels of acetylcarnitine and long-chain acylcarnitine remained relatively unchanged. In freshly ejaculated monkey spermatozoa, about 45% of the acid-soluble carnitine was in the acetylated state. This value dropped to about 15% in cells incubated without substrate and increased to about 70% in cells incubated with glucose or fructose. Total acid-soluble CoA concentrations in bovine and monkey spermatozoa were 0.96 and 2.0 nmoles/ 10' cells, respectively: when the cells were incubated in fructose or glucose, the increases in the acetylation state of CoA were similar to those in carnitine. Thus the acetylation of carnitine plays an important role in normal spermatozoan metabolism and the carnitine:carnitine acetyltransferase system appears to buffer against rapid changes in the concentration of acetvl-CoA.

Summary Six juvenile Macaca fascicularis relatively unfamiliar with one another were placed together in a large play apparatus. The Boelkins' water test was used to establish dominance. After one hour of social interaction the animals formed a stable hierarchy. Following six days of observation of this group, the dominant male and female were removed. This removal drastically altered the behavior of the remaining animals (19 of 40 behavior categories changed significantly). A replication indicated that behavior in one group allowed predictions of future behavior in that group, but did not allow predictions to an autonomous segment of the original group.

A study was done to directly compare percutaneous absorption of selected compounds in the rhesus monkey and in man. Hydrocortisone, testosterone, and benzoic acid in the monkey showed the same low, middle, and high absorption as in man. Total percents absorbed were similar in the monkey and man. The rhesus monkey may be a suitable animal model for percutaneous absorption studies of relevance to man.

Interest in the Ir genes of rheus monkeys stems from their phylogenetic relationship to man and the extensive data already available on the major histocompatibility complex of the monkey. At least two independent dominant H-linked Ir genes have been identified in the rhesus. These genes control the ability of monkeys to respond to the random linear copolymer of glutamyl alanine (GA), or the dinitrophenyl conjugate of glutamyl lysine (DNP-GL). These synthetic polymers can elicit weak delayed-type skin reactions and strong humoral responses in some monkeys. In a series of unrelated monkeys phenotyped for the serologically defined RhL-A specificities of both segregant series, there were no correlations between any RhL-A specificity and responder status to the GA or DNP-GL polymers. However, segregation analysis of 21 rhesus families sired by 3 fathers indicated the capacity of the offspring to form antibodies was associated with genes coded for in the RhL-A complex. In three monkeys, verified recombination within the RhL-A complex between the genes coding for the serologically defined determinants (SD loci) and the gene(s) controlling the lymphocyte-activating determinants (Lad loci) responsible for mixed lymphocyte reactivity was established. In two of these monkeys the immune response genes controlling the DNP-GL response segregated with the Lad genes, while in the third case the Ir-GL gene segregated with the SD loci, tentatively localizing the Ir-GL gene between the SD and Lad loci. In addition, we have shown that genetically distinct genes control responsiveness to DNP-GL and GA. These genes were separated by recombination, thus one monkey inherited the Lad, Ir-GL, and SD loci from one paternal haplotype and by crossing over inherited the gene controlling GA responsiveness from the other paternal haplotype. The fine structure mapping of the RhL-A gene complex is compared with the H-2 and HL-A gene complexes. Several striking similarities were noted.

Lethally irradiated rhesus monkeys were used for bone marrow allografting and autografting. Monkeys receiving allogeneic bone marrow developed acute graft-versus-host reaction (GVHR) and had a mean survival time of 9.1 days as compared to autografted monkeys which survived above 500 days. Treatment with antilymphocyte sera (ALS) before allografting modified the GVHR and extended the survival time to an average of 43 days. Histologically, such animals showed evidence of "chronic" GVHR and septicemia secondary to a lack in lymphoreticular recovery. Subsequently, severe GI-tract infections followed which usually served as portal of entry for septicemia.

Between the 50th day of embryonic life and the 30th week of gestation no reconstructions of the developing parenchyma of the human lung seem to have been attempted. To bridge this long gap, only two techniques have been utilized hitherto: counting the generations of branches in the growing segments of the lung and analyzing the changing cytology with the aid of the electron microscope. At least two important objectives remain: a knowledge of when the respiratory units known as pulmonary acini appear and the order in which capillary invasion of its component parts takes place. At the 16th week of gestation, peripheral units have not attained their full complement of branches and their boundaries are not delimited. At 17 weeks, acini of varying sizes can be recognized as discrete terminal units at the periphery of the segmental trees, having attained their full, though underdeveloped, complement of fetal branches, as gauged by later counts of generations made at 30 weeks of age (Boyden, '69). The 17th is also the week in which capillaries first invade the peripheral branches of the acinus. Although significantly later stages have not yet been obtained, the evidence available (including that from unpublished work on monkey fetuses) strongly suggests that canalization (before birth), like alveolization (after birth)proceeds mainly in a centripetal direction.

SummaryHeterologous double-antibody radioimmunoassay methods are described for the measurement of circulating levels of rhesus monkey (Macaca mulatto) FSH and LH; the latter assay is also applicable to rhesus chorionic gonadotropin (CG) estimations. The FSH assay utilizes purified rat FSH for trace, either of two anti-human FSH antisera and a semipurified rhesus pituitary standard. The LH assay utilizes purified ovine LH for trace, an anti-human CG antiserum and the same rhesus pituitary standard. The use of these systems obviates the necessity of purifying rhesus gonadotro-pins which are required for the development of homologous radioimmunoassay systems.

An investigation has been made of the ocular responses in rabbits, primates, and man to the selective β2-adrenergic agonist salbutamol and to the mixed α, β-adrenergic agonist, isoproterenol. The time courses of the pressure responses to topical applications of the drugs were characterized by a rapid onset of decreased pressure followed by a slow but varied rate of recovery. No dilatation of the pupil could be induced either by topical or intravitreal injections of salbutamol, but the pressure responses could be blocked by prior administration of the adrenergic β-receptor antagonist propranolol. Isoproterenol applied topically and by intravitreal injection caused both α- and β-adrenergic responses, and these could be separated by dosage. A pressure response occurred at doses of isoproterenol that were inadequate to cause pupil dilatation, and this could be blocked by propranolol. At high dosage, pupil dilatation occurred and this could be blocked by the α-adrenergic receptor antagonist phenoxybenzamine. Analysis of aqueous humor dynamics in rabbits and man showed that the pressure reduction to salbutamol was associated with a decrease in the rate of aqueous humor formation, and a small but variable increment in the facility of outflow. It is concluded that the time course of the pressure responses in man, in conscious rabbits, and in lightly sedated monkeys to β-agonists are similar and involve similar changes in aqueous humor dynamies. Further, it was found that the β pressure responses differ fundamentally from those resulting from stimulation of α-adrenergic receptors.

Marmoset serum or serum of other species of animal may react with sodium dodecyl sulfate and forms nonspecific precipitin lines in agar diffusion. The protein detergent complexes are not readily dialyzable. Therefore precipitin lines derived from studies that use sodium dodecyl sulfate-treated antigens in agar diffusion must be interpreted with caution.

Hybridization studies with a [ 3 H]DNA probe from an endogenous baboon type C virus were used to detect nucleic acid sequences of type C virus in primate cellular DNA. Sequences related to those of the baboon type C virus are found in all other Old World monkey species, higher apes, and man.

Electrical properties of gallbladders from several species were investigatedin vitro. Gallbladders were mounted as a flat sheet in a Lucite Ussing-type chamber and bathed on each surface with buffered HCO3-free Ringer's solution. Rabbit and dog gallbladders developed a mean transmural electrical potential difference (p.d.), not significantly different from zero, whereas gallbladders of goose, monkey and man developed serosa-positive p.d.'s which were dependent on the availability of O2 and were abolished by ouabain and low temperatures. The short-circuit current (SCC) was dependent on the presence of Na in the bathing medium; choline and K were ineffective substitutes. Bromide replacement for CI reduced SCC by less than 15% in goose and monkey gallbladders; sulfate replacement eliminated SCC. Isethionate replacement maintained some SCC in gallbladder of monkey but not of goose. The presence of HCO3 in the bathing medium abolished SCC in goose gallbladder but increased slightly SCC in gallbladders of monkey and man. To determine whether the anion-cation selectivity of gallbladders from each species correlated with the magnitude and orientation of the spontaneous p.d., diffusion potentials were artificially established by diluting the mucosal solution 50% with isotonic mannitol. Gallbladders from all species studied are cation-selective. Epithelial removal demonstrated that the primary site of tissue resistance and the ability to discriminate between cations and anions resides in the epithelium. In view of the cation selectivity of these tissues it is unlikely that local osmotic gradients, established in the lateral intercellular spaces during NaCl absorption, are the cause of serosapositive p.d.'s seen in the goose, monkey and human gallbladders.

Current developments in the pharmacology of neuromuscular blocking agents indicate that within the next several years, nondepolarizing drugs of short and intermediate duration of action, devoid of significant side effects, may become a reality. The important factors which may permit their development are reviewed.

An abnormal but apparently successful sexual posture was observed in an adult male rhesus monkey in which the subject bit its hands and leg in the process of dismounting. This behavior followed each of several mounts but ceased toward the end of the series, culminating in ejaculation. The animal's rearing history is included, suggesting that early partial isolation may produce long-lasting abnormalities which, while unusual, need not seriously affect successful copulation.

Intestinal introluminal pressure was measured in vivo in anesthetized guinea pigs, dogs, cats ad monkeys. In guinea pigs, but not in the other species, the intestinal stimulatory effect of 5-hydroxytryptamine was antagonized by morphine. The 5-HT-blocking action of morphine in intestine seems to be unique to the guinea pig.

Circuits and methods are described for converting an inexpensive, commercially available model airplane radio control transmitter-receiver system to a lightweight telestimulation system for primates. Conversion of the transmitter produces 60 cps pulses in trains of any desired leghth. Two methods of converting receiver outputs to biphasic constant current square wave pulses are discussed. The completed receiver-stimulator weighs 63 g and is small enough to be mounted on the skull of a juvenile rhesus monkey.

The IgG fraction of equine antithymocyte globulin administered by the intravenous and intramuscular route to two patients with severe thermal injury was associated with survival of the skin allografts to 19 and 42 days. In the second patient the IgG fraction was discontinued 28 days after skin grafting and rejection occurred 14 days later while the patient was receiving azathioprine and 1% topical hydrocortisone cream to the skin allografts. Although no comparison can be made between the immunosuppressive properties of antithymocyte globulin, azathioprine and topical steroids, skin allograft survival was prolonged temporarily until autograft skin from previous donor sites could be obtained. The use of skin allografts protected by immunosuppressive therapy in patients with severe thermal injury deserves further consideration.

The effect of varying the ratios of dietary fat, protein and carbohydrate on the amount and composition of fecal output was studied in adult, male pig-tailed monkeys (Macaca nemestrina) fed liquid, fiber-free semisynthetic diets. The dietary nitrogen was supplied as an enzymatic protein hydrolyzate (biological value = 86%), the fat as corn oil, and the carbohydrate as corn syrup solids. Vitamins and minerals were added to meet the nutritional requirements of this monkey. Nine diets were fed for 2 weeks, and fecal excreta collected daily after 4-day adaptation to a new diet. The levels of protein/day were 40, 80, and 160 kcal/animal and the levels of fat/day were 4.5, 22.5, and 112.5 kcal/animal. Carbohydrates were adjusted to maintain the diets isocaloric (700 kcal/day per monkey). The assumption was made that a) there was no time trend, and b) that the preceding diet had no carry-over effect on the next diet being tested. Results suggest that total fecal output was greater on the high protein diets, especially when fat levels were either 4.5 or 112.5 kcal. The 22.5 kcal fat and 160 kcal protein did not show an increase in fecal output. These fecal output differences were related to changes in fecal moisture but not in dry fecal matter. Increased nitrogen loss in the feces was noted for all 160 kcal protein diets, and especially so when the fat level was 4.5 kcal. The 112.5 kcal fat diet produced feces higher in total lipids. If a fiber-free formula diet is designed to induce a minimum of fecal bulk, the most satisfactory formulation appears to be one with a moderate amount of dietary fat, and a protein content in the general range of the recommended daily allowance.

Unit recordings were performed in the caudate nucleus of awake macaques. Animals were maintained in a restraining chair and had been trained to perform various types of elaborate movements to obtain food-reward. Three types of movement were studied: (a) natural, large gestures of grasping solid food (peanut) from a tray and bringing it to the mouth; (b) small amplitude lever-pressing movements for fluid reward (fruit juice), mainly involving distal segments (fingers, wrist); (c) same as (b), but involving essentially proximal musculature, and consisting of an ample isotonic pulling with arm and shoulder. Units were recorded before and during each of the preceding types of movements (but in different animals). Results indicate that: (1) caudate cells were encountered in all 3 cases which were accelerated during different stages of the movement; (2) more cells were activated in situations (a) and (b) than (c); (3) very few cells displayed inhibition instead of excitation; (4) among cells modified during movement, very few were also accelerated through passive flexions or extensions of the forelimb; (5) some caudate cells were also clearly activated through various visual or auditory intercurrent stimuli, probably arousing the animal's attention.

1. 1. Secretory proteins from the salivary glands of Macaca irus and Cercopithecus aethiops were obtained by the tissue culture technique. 2. 2. Data from isoelectric focusing, gel filtration and immunodiffusion showed extensive similarities between the individual glands of the two species. 3. 3. Immunological identity was present between the three main protein components of submandibular tissue from M. irus and C. aethiops, but the main components of the submandibular glands were not identical with the corresponding sublingual components. One submandibular component was common to the parotid gland secretion.

The catabolism and distribution of rhesus and baboon asialotransferrins relative to the corresponding parent proteins were studied in rabbits using a dual isotope tracer technique. Also a similar study with the baboon proteins in a baboon is reported.The metabolic data obtained in rabbits with both rhesus and baboon transferrins was close to the values established in a previous study for rabbit transferrin. Desialylation resulted in an average increase in the fractional catabolic rate of rhesus transferrin by 22.7%. This change is similar to that found earlier with asialotransferrins from several nonprimate mammals which are thought not to interact with the hepatic asialoglycoprotein receptor.Two kinetically distinct fractions were identified in baboon asialotransferrin. One of these, amounting to approximately one-third of the protein, was eliminated from the circulation very rapidly. The remaining two-thirds constituted a slowly catabolized fraction which behaved in vivo similarly to rhesus asialotransferrin. Unlike the rapidly cleared fraction, elimination of the slowly catabolized fraction in baboon asialotransferrin is probably not mediated by the hepatic asialoglycoprotein receptor. An amount comparable to the rapidly eliminated fraction in baboon asialotransferrin was recovered with the liver of rats in short-term experiments. In rats which were preinjected with chicken acid α1-glycoprotein the hepatic uptake of baboon asialotransferrin was markedly reduced. Data obtained in the baboon agreed with the findings in rabbits, although transferrin turnover was slower in the baboon.From its behavior in vivo as an asialoglycoprotein, baboon transferrin shows greater resemblance to human transferrin than rhesus transferrin. This conclusion is supported by carbohydrate analyses which show an intermediate position for baboon transferrin between man and a nonprimate mammal (rabbit), and a similarity between rhesus and rabbit transferrins.

Indirect hemagglutinating (IHA) antibody responses to Herpesvirus hominis types 1 and 2 (HVH-1 and HVH-2) were compared to complement-fixing and neutralizing antibody responses in immunized laboratory animals (rabbits, guinea pigs, and hamsters) and in natural infections of man. With the immunized animals, type specificity was seen only in the IHA test and only with antisera produced in hamsters and in the rabbits immunized with HVH-2. In human nongenital infections (considered to be caused predominately by HVH-1), IHA and neutralizing antibodies developed at about the same rate and reached approximately the same levels for HVH-1 and HVH-2. IHA titers tended to be higher than neutralizing antibody titers for both virus types. In genital infections (considered to be caused predominately by HVH-2), there was a rapid IHA antibody response to HVH-2, and the early HVH-2 antibody demonstrable by IHA, but not by neutralization tests, was found to be immunoglobulin M in nature. In genital infections, IHA titers for HVH-2 were markedly higher than neutralization titers, but there was no pronounced difference in neutralizing the IHA antibody titers for HVH-1. Several patients with genital infections fialed to develop IHA antibody for HVH-1. The IHA test possessed no greater sensitivity than did complement fixation or neutralization tests for serodiagnosis of HVH infections. Despite the fact that a number of patients with genital infections produced IHA antibody only for HVH-2, the test was no more effective than the neutralization test in providing a type-specific serodiagnosis of infection, due largely to the fact that the rapid IHA antibody response to HVH-2 prevented demonstration of a further, significant antibody titer increase in a number of cases.

—Evidence is presented for the presence of two acidic metabolites of dopamine, 3,4-dihydroxyphenylacetic acid (DOPAC) and homovanillic acid (HVA) in the sympathetic ganglia of some mammalian species other than ruminants. In the pig, electrical stimulation of the preganglionic nerves to the superior cervical ganglion results in a mean increase of 78 per cent in the concentration of HVA and a mean increase of 372 per cent in the concentration of DOPAC in this sympathetic ganglion. These results can be interpreted as further evidence for the involvement of dopamine in transmission at sympathetic ganglia.

Extract: This study characterizes the circulatory changes associated with asphyxia in the newborn monkey and examines the effect of phenobarbital on asphyxia. The time to last gasp and duration of total asphyxia as well as heart rate at the start of resuscitation were the same in the phenobarbital-treated and untreated infants. Initial cardiac output was the same in both groups; there was a profound drop in cardiac output with asphyxia which was the same in both groups. Organs which preferentially receive a greater percentage of cardiac output during asphyxia are heart, total brain, and adrenal glands. Organs receiving a decreased percentage of cardiac output during asphyxia are kidneys, liver, and gastrointestinal tract. Cerebral hemisphere flow as a percentage of cardiac output is maintained during asphyxia, whereas paleoencephalon flow as a percentage of cardiac output increases significantly. These data confirm the circulatory redistribution of cardiac output in response to asphyxia described previously in the monkey fetus. The treated infants did not show the prolongation of time to last gasp reported in the monkey fetus; the dose of phenobarbital we used, although adequate to produce sedation, may have been too low to demonstrate the protective effect. Speculation: The long term survival status of infants with neonatal diseases such as severe meconium aspiration or hyaline membrane disease which are frequently accompanied by varying degrees of asphyxia might be improved by including phenobarbital in the treatment regimen if a protective effect were conclusively demonstrated.

1 The reaction of tritiated propylbenzilylcholine mustard ([3H]-PrBCM; N-2′-chloroethyl-N-[2″,3″-3H2] -propyl-2-aminoethylbenzilate) with homogenates of mammalian brain has been studied. 2 The uptake can be divided into an atropine-sensitive component of fixed capacity (380 pmol/g protein in the rat) and an atropine-insensitive part. 3 The atropine-sensitive portion is identified as muscarinic receptor by its insensitivity to nicotinic antagonists and anticholinesterases and its sensitivity to a range of muscarinic antagonists. 4 The uptake of [3H]-PrBCM is also inhibited by muscarinic agonists and there is reasonable quantitative agreement between the affinities of agonists estimated in this way and in intact tissues by physiological responses. 5 The fraction of [3H]-PrBCM uptake inhibited by muscarinic antagonists and agonists is the same. 6 The amount of receptor found in six mammalian species was inversely related to the size of the brain, but the rates of alkylation and the sensitivity to atropine were not dissimilar.

Rhesus monkeys were fed a high-fat diet containing either 0, 43, or 129 µg/kcal of cholesterol for 18 months. In the monkeys on the cholesterol-supplemented diets, changes in plasma cholesterol remained within the range found in monkeys fed the cholesterol-free diet. Monkeys on the cholesterol-supplemented diets were compared with monkeys given no dietary cholesterol with range-matched plasma cholesterol; intimal thickness of the aorta and branch arteries, distribution of lipoprotein cholesterol, and tissue content of cholesterol in aorta and liver were considered. The monkeys on the cholesterol-supplemented diets showed intimal thickening with more sudanophilia and increased aortic cholesterol, a decrease in plasma high-density lipoprotein cholesterol, and an increase in low-density lipoprotein cholesterol, and the monkeys fed the higher amount of dietary cholesterol showed an increase in hepatic cholesterol. No null point for the effect of dietary cholesterol on arterial intima was found even at an intake level far below that conventionally used for the induction of experimental atherosclerosis in the nonhuman primate. The intimal changes found in response to very low cholesterol intake imply that subtle qualitative alterations in lipoproteins are of critical importance to our understanding of lesion induction.

The inferior olivary nuclear complex is generally considered to be the major source of climbing fibers to the cerebellum (Bell and Dow, '67). To test the validity of this statement, experiments using monkeys were designed in which the olivocerebellar fibers were transected in their course through the medulla to the contralateral hemicerebellum. After allowing for anterograde degeneration of these transected fibers, the cerebellum of each monkey was stained and examined for the presence and condition of climbing fibers. In each monkey olivocerebellar fibers were transected at one of three sites: (1) within the right inferior olivary nucleus in one rhesus monkey, (2) at the decussation of the olivocerebellar fibers, within the region of the raphe, in five monkeys and (3) in the left parasagittal plane, just lateral to the inferior olivary nucleus, in one monkey. No noticeable reduction was found in the number of silver stained climbing fibers associated with the Purkinje cells of each hemicerebellum after these lesions. None of the monkeys exhibited durable, specific cerebellar signs. On the basis of the histological evidence obtained from the above experiments, it is concluded that the inferior olivary complex is not the major source of climbing fibers to the cerebellum. Climbing fibers were readily identified in each of the sections examined. However, silver-stained climbing fibers were not associated with many Purkinje cells in every one of these sections. There were 1.7 times more Purkinje cells without climbing fibers than those with climbing fibers. This ratio of 1.7 to 1 characterized normal cerebella as well as both hemispheres of the cerebella of the cerebella of the experimental monkeys.

Thalamic afferents to Macaque prefrontal cortex from the mediodorsal nucleus were examined by techniques specific for anterograde degeneration and axoplasmic transport. The sampling procedure employed permits establishing the extent of topographic projections to cortex from subcortical foci for the same brain which was surveyed subsequently in tracing specific neuronal connections by electron microscopy. Topographic and general laminar distribution of thalamic terminals are presented in terms of 3 subareas of prefrontal cortex. The dorsolateral and ventral (orbital) surfaces of prefrontal cortex receive respectively projections from the lateral and medial subdivision of the mediodorsal nucleus. In addition, the medial wall of the frontal lobe, including the dorsomedial part of the lateral convexity, heretofore regarded as athalamic, receives input from the caudal-dorsomedial aspect of the mediodorsal nucleus. Preliminary evidence suggests that axons from the mediodorsal nucleus terminate in the head of caudate nucleus, as Sachs81 described 65 years ago in the first orthograde study of thalamo-prefrontal cortex connections.

This study was designed to determine the presence of cell-bound histamine and mast cells, if any, in the lung and skin of nonhuman primate fetuses and neonates. The results indicate that cell-bound histamine can be detected in both tissues of the rhesus monkey fetus by 60 days of gestation, the earliest age examined, at levels that are 2% to 3% of levels present in yearling animals. Levels increase markedly during the last life mo of gestation; however, at birth, levels are only 12% to 46% of those observed in the yearling and are lower than levels observed at 150 days of gestation. Mast cell numbers in lung and skin of the fetus closely parallel histamine content.

Epithelial proliferation of various regions of macaque gingival epithelium, as measured by uptake of locally injected H3-thymidine, showed regional differences which could be explained in part by the size and nature of the inflammatory infiltrate invariably found in gingival biopsies. The proliferative activity of oral sulcular epithelium was greater than that of oral epithelium and was negatively correlated with the size of the area of infiltrated connective tissue. On the other hand labelling of oral epithelium was positively correlated with size of infiltrate, the effect decreasing with distance of the epithelium from the infiltrate

It has been possible to demonstrate a direct relationship between number of sporozoites in an inoculum and the number of subsequent relapses in experimental infections with Plasmodium cynomolgi. The reduction in Sporozoite numbers was accomplished through the use of two techniques; (1) X-irradiation and (2) volumetric dilution. The authors conclude that these observations tend to support a concept of latency as an explanation for relapse and delayed patency in malaria. It is difficult to reconcile these results with the generally accepted concept of a continuous cycle of liver schizogony in relapsing malarias.

A comlex of polyriboinosinic-polyribocytidylic acid (poly I-poly C) with poly-L-lysine and carboxymethylcellulose has been prepared. This complex is five to 10 times as resistant to hydrolysis by primate serum as the parent poly I-poly C. It has a thermal denaturation temperature about 40 C higher than that of poly I-poly C. The complex induces significant levels of serum interferon in monkeys and chimpanzees under conditions in which poly I-poly C itself induces no interferon.

6 protein-malnourished rhesus monkeys were nutritionally rehabilitated by placing them on diets high in protein content. At 60 and 180 days following the initiation of the rehabilitation program, experimental animals and 4 high-protein dietary controls were tested on a preference task designed to determine reactions to foods containing differing quantities of protein and to novel stimuli. Each S was presented a choice of diets containing 2%, 3.5%, or 25% protein, as well as non-food objects. The results indicated that the aversion to novel stimuli (neophobia) and the preference for high-protein food previously reported in protein-malnourished monkeys did not persist following 180 days of rehabilitation. The results suggest that at least part of the behavioral syndrome associated with protein-calorie malnutrition may be improved by 6 mo. of nutritional rehabilitation.

In normothermic rhesus monkeys ( Macaca mulatta ) blood flow to the brain was completely interrupted for 1 h, and then restored for different periods from 45 min to 24 h. Neuronal function was monitored by recording the electrocorticogram (ECoG) and the pyramidal response (PR) to the electrical stimulation of the motor cortex. In addition, cerebral blood flow, intracranial pressure, epicortical pH, blood gases, blood glucose, hematocrit, coagulation times, and serum electrolytes were repeatedly measured. During ischemia, the ECoG was suppressed within 15 sec, and the pyramidal response within a few min. In 11 out of 19 animals the PR and — at survival times of more than 90 min — electrocortical activity returned upon recirculation. In 8 animal recovery of neuronal function did not occur, presumably because of an impaired blood recirculation of the brain. Reduction in post-ischemic blood flow resulted from the combined effect of post-ischemic brain swelling with consequent increased in intracranial pressure, microcirculatory disturbances, and post-ischemic hypotension. In one case the circulatory disturbance was restricted to circumscribed areas causing typical boundary zone lesions in the pallidum and parietal lobe.

Recovery of beta-sitosterol, glycerol triether (1-hexadecyl-2,3-didodecyl glycerol triether), and chromic oxide was studied in African green monkeys and stumptail macaques consuming diets containing 0.75 mg/Cal cholesterol and 38% of calories as safflower oil or butter. Following oral administration of these compounds, feces were collected daily for 9 days. For all animals, excretion of beta-sitosterol and glycerol triether paralleled one another almost exactly. Except for two animals, this was also true for chromic acid. Essentially 100% of the administered beta-sitosterol and 90-95% of the glycerol triether were recovered; excretion of these markers virtually was complete by day 3. Ninety-two percent of the beta-sitosterol was isolated in the nonsaponifiable lipid extract of the feces with less than 6% in the remaining aqueous phase. A maximum of 3.1% of the beta-sitosterol and 1.8% of the glycerol triether were found in the blood. For stumptail macaques, the major excretory form of beta-sitosterol was the 5 beta-derivative. African green monkeys were more variable; one animal excreted the bulk of the beta-sitosterol unchanged while others excreted greater than 80% as the ring-saturated 5 beta-derivative. Animals consuming the safflower oil containing diet consistently excreted a greater percentage of the beta-sitosterol unchanged, compared with those animals eating the butter containing diet. There was no evidence for steroid ring degradation in any of the animals used in this study.

Experiments were made on the posterior parietal association cortical areas 5 and in 17 hemispheres of 11 monkeys, 6 M. mulatta and 5 M. arctoides. The electrical signs of the activity of single cortical cells were recorded with microelectrodes in waking animals as they carried out certain behavioral acts in response to a series of sensory cues. The behavioral paradigms were one for detection alone, and a second for detection plus projection of the arm to contact a stationary or moving target placed at arm's length. Of the 125 microelectrode penetrations made, 1,451 neurons were identified in terms of the correlation of their activity with the behavioral acts and their sensitivity or lack of it to sensory stimuli delivered passively; 180 were studied quantitatively. The locations of cortical neurons were identified in serial sections; 94 penetrations and 1,058 neurons were located with certainty. About two-thirds of the neurons of area 5 were activated by passive rotation of the limbs at their joints; of these, 82% were related to single, contralateral joints, 10% to two or more contralateral joints, 6% to ipsilateral, and 2% to joints on both sides of the body. A few of the latter were active during complex bodily postures. A large proportion of area 5 neurons were relatively insensitive to passive joint rotations, as compared with similar neurons of the postcentral gyrus, but were driven to high rates of discharge when the same joint was rotated during an active movement of the animal...

Depth perception in the monkey ( Macaca mulatta and Macaca nemestrina ) was evaluated quantitatively using the method of constant stimuli with the Howard Dolman test—two vertical rods. one of which varies in depth. The behavioral task was an automated. discrete trial discrimination with two levers and an observing response of placing the head in a face mask. Threshold disparity angle for the one monkey completing training was 2.4″ of arc. Best results for another monkey corresponded to a disparity angle of 15.2″ of arc. The best of six human subjects tested with the same apparatus had threshold disparity angles of 2.3 and 2.5″ of arc. Luminance effects on stereoacuity were measured and replicated with the monkey. The results compare closely with those of a human subject with the same apparatus and with published data on man obtained under similar conditions. Under monocular viewing conditions. the monkey did not exceed chance levels of performance even after extensive training. A human subject viewing monocularly had a threshold disparity angle of 58″ of arc. These results are consistent with the argument that binocular diparity is the cue used in this task and that stereopsis in the monkey is comparable to stereopsis in man.

An attempt has been made to establish, so far as possible, the specific types of synaptic bulbs on motoneurons which arise from extrinsic (descending and dorsal root) and intrinsic sources (interneurons). This has involved the laborious analysis of thousands of electron micrographs of material from normal motoneuron neuropil, and motoneuron neuropil of animals with lesions of spinal tracts, spinal roots, and motor cortex. Our studies have established that the large synaptic bulbs on dendrites, which are the only type in the spinal cord to possess pre-synaptic synapses (serial synapses), are derived from monosynaptic dorsal root fibers (R bulbs). The presynaptic component of the serial synapse appeared to degenerate at levels below spinal cord transections (P bulbs). By means of transections of spinal cord we have found that descending fibers in the spinal cord terminate as one of at least two distinct classes of synaptic bulbs, one with spheroid synaptic vesicles (S) and one with flattened vesicles (F). There is evidence from several sources that the first type may often be excitatory in function and the second type inhibitory. Only synaptic bulbs with spheroid vesicles show definite signs of degeneration after lesions of the opposite motor cortex. The large (L) synaptic bulbs on motoneuron somata, associated with subsynaptic cisterns, are clearly not derived from the descending systems, or from posterior root fibers.