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The NIH Brain Research through Advancing Innovative Neurotechnologies (BRAIN) Initiative is focused on developing new tools and neurotechnologies to transform our understanding of the brain, and neuroethics is an essential component of this research effort. Coordination with other brain projects around the world will help maximize success.

The peptide content of individual mammalian cells is profiled using matrix-assisted laser desorption/ionization (MALDI) time-of-flight mass spectrometry. Both enzymatic and nonenzymatic procedures, including a glycerol cell stabilization method, are reported for the isolation of individual mammalian cells in a manner compatible with MALDI MS measurements. Guided microdeposition of MALDI matrix allows samples to be created with suitable analyte-to-matrix ratios. More than 15 peptides are observed in individual rat intermediate pituitary cells. The combination of accurate mass data, expected cleavages by proteolytic enzymes, and postsource decay sequencing allows identification of 14 of these peptides as proopiomelanocortin prohormone-derived molecules. These protocols permit the classification of individual mammalian cells by peptide profile, the elucidation of cellspecific prohormone processing, and the discovery of new signaling peptides on a cell-to-cell basis in a wide variety of mammalian cell types.

Research indicates that human airway smooth muscle (HASM) cell proliferation is stimulated by the bioactive lipid mediator lysophosphatidic acid (LPA) and may cause abnormal proliferation in diseased smooth muscle. LPA may work with epidermal growth factor to stimulate cellular division. Studies show that the rate of [3H] thymidine incorporation is much greater when both LPA and EGF are administered at the same time. HASM cells are ideal for future research into synergistic regulation and asthma disease.

Abstract Background Topographic reorganization of central maps following peripheral nerve injury has been well characterized. Despite extensive documentation of these physiological changes, the underlying anatomical correlates have yet to be fully explored. In this study, we used Golgi impregnation and light microscopy to assess dendritic morphology following denervation of the glabrous hand surface in adult primates. Results After survival durations that permit complete physiologically-defined reorganization, we find a systematic change in the dendritic arborization pattern of both layer II/III pyramidal and layer IV spiny stellate cells in the contralateral hand region of area 3b, compared to unaffected cortical areas. In general, our analyses indicate a progressive expansion of distal regions of the dendritic arbor with no appreciable changes proximally. This pattern of distal dendritic elaboration occurs for both basilar and apical dendrites. Conclusions These observations are consistent with the notion that latent inputs gain expression in reorganized cortex after nerve injury via their influence through contacts with more distally located termination sites.

Abstract: In the present study, we examined the relationship between post-injury survival duration and receptive field size at multiple levels of the ascending somatosensory neuroaxis. In experimentally naïve subjects, receptive fields on the glabrous hand are typically restricted to single digits. Yet, following targeted nerve section, receptive fields often span multiple digits. In these experiments, adult squirrel monkeys were subject to paired transections of the median and ulnar nerves and permitted to survive for varying periods (2–28 months) prior to terminal electrophysiological recording. The frequency of cutaneously activated multiple-digit receptive fields was evaluated in regions of brainstem, thalamus and cortex normally devoted to the (now) partially deafferented hand. We report that for area 3b of primary somatosensory cortex, receptive field size became smaller as a function of survival duration. In contrast, survival duration had no appreciable effect on the frequency of multiple-digit receptive fields in either the cuneate nucleus of the brainstem or the ventroposterior lateral nucleus of the thalamus. These observations suggest that the mechanisms responsible for the refinement of receptive fields are, primarily, resident to the cortex. [Copyright &y& Elsevier]

Background: Topographic reorganization of central maps following peripheral nerve injury has been well characterized. Despite extensive documentation of these physiological changes, the underlying anatomical correlates have yet to be fully explored. In this study, we used Golgi impregnation and light microscopy to assess dendritic morphology following denervation of the glabrous hand surface in adult primates. Results: After survival durations that permit complete physiologically-defined reorganization, we find a systematic change in the dendritic arborization pattern of both layer II/III pyramidal and layer IV spiny stellate cells in the contralateral hand region of area 3b, compared to unaffected cortical areas. In general, our analyses indicate a progressive expansion of distal regions of the dendritic arbor with no appreciable changes proximally. This pattern of distal dendritic elaboration occurs for both basilar and apical dendrites. Conclusions: These observations are consistent with the notion that latent inputs gain expression in reorganized cortex after nerve injury via their influence through contacts with more distally located termination sites. [ABSTRACT FROM AUTHOR]

Opioid receptor signaling via EGE receptor (EGFR) transacti- vation and ERK/MAPK phosphorylation initiates diverse cellu- lar responses that are cell type-dependent. In astrocytes, multiple μ opioid receptor-mediated mechanisms of ERK activation exist that are temporally distinctive and feature different out- comes. Upon discovering that chronic opiate treatment of rats down-regulates thrombospondin 1 (TSP1) expression in the nucleus accumbens and cortex, we investigated the mechanism of action of this modulation in astrocytes. TSP1 is synthesized in astrocytes and is released into the extracellular matrix where it is known to play a role in synapse formation and neurite out- growth. Acute morphine (hours) reduced TSP1 levels in astrocytes. Chronic (days) opioids repressed TSP1 gene expression and reduced its protein levels by g.μ opioid receptor and ERK-dependent mechanisms in astrocytes. Morphine also depleted TSP1 levels stimulated by TGFβ1 and abolished ERK activation induced by this factor. Chronic morphine treatment of astrocyte-neuron co-cultures reduced neurite outgrowth and synapse formation. Therefore, inhibitory actions of morphine were detected after both acute and chronic treatments. An acute mechanism of morphine signaling to ERK that entails depletion of TSP1 levels was suggested by inhibition of morphine activa- tion of ERK by a function-blocking TSP1 antibody. This raises the novel possibility that acute morphine uses TSP1 as a source of EGF-like ligands to activate EGFR. Chronic morphine inhibi- tion of TSP1 is reminiscent of the negative effect of μ opioids on EGFR-induced astrocyte proliferation via a phospho-ERK feedback inhibition mechanism. Both of these variations of classical EGFR transactivation may enable opiates to diminish neurite outgrowth and synapse formation. [ABSTRACT FROM AUTHOR]