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In order to record the stepping activity in little size mammals, it was planned a set able to transform the stepping activity of the animals in electrical signals displayed on a polygraph. The set is formed by a complex transmitter-receiver, and transformer-recorder, that allow to record also high frequency stepping activity and its time variations.

The conditioning stimulation of the substantia nigra both in chronic and acute cats determined a more effective inhibition than caudate nucleus activation on the evoked paroxysmal activity in the amygdala. Lesions of the substantia nigra by means of kainic acid, produced the disappearance of the inhibition induced by caudate nucleus. An examination of the obtained data and of the literature on this topic, allowed us to identify a possible nigro-amygdaloid direct pathway.

The effects of VTA stimulation on the quiet biting attack evoked by hypothalamic activation in the cat, were studied. The reference value of the aggressive behaviour was the latency of the biting. Concurrent activation of both the hypothalamus and VTA determined a decrease of the biting latency, which depended on the parameters of VTA stimuli. The facilitatory effect of the dopaminergic mesolimbic system on the attack behaviour is emphasized.

In order to investigate the functional meaning of the connections between the claustrum and the controlateral motor areas, the extracellular spontaneous activity of 81 PTNs was recorded. Single shock controlateral claustrum stimulation inhibited twenty-two out of the 81 PTNs. On four of the twenty-two PTNs the inhibition was preceded by an early activation. The split of the corpus callosum was performed in 5 cats in order to study the pathway followed by claustrum fibers to the controlateral motor cortex. It is ipothesized that the relationship between the claustrum and controlateral area 4 and 6 PTNs might have the purpose of giving the pyramidal output the bilateral contribution of a plurisensory structure.

Nigral injection of kainic acid determines an inhibition of the after-discharges evoked in the amygdala by stimulation of the ipsilateral piriform cortex and later an increase of the AD duration. The role of the substantia nigra in the control both of the paroxysmal phenomena localized in the amygdala and of its spontaneous activity is emphasized.

The role of the substantia nigra on the quiet biting attack evoked by hypothalamic stimulation was investigated. Simultaneous activation of the hypothalamus and of the s. nigra determined a significant increase of the biting latency or in some case the disappearance of the attack pattern. The inhibitory role of the s. nigra on the quiet biting attack evoked by hypothalamic stimulation is discussed.

The conditioning stimulation of the globus pallidus both in chronic and acute cats determined a more effective inhibition than caudate nucleus activation on the evoked paroxysmal activity in the amygdala. Lesions by means of kainic acid of the entopeduncular nucleus, has resulted in a significant decrease of the caudate inhibitory effect. The hypothesis we assumed is about a role of the globus pallidus in the control of the evoked amygdaloid after-discharge.

Intrapeduncolar intrapeduncolar entopeduncolar injection of kainic acid determines an early decrease of the evoked amygdaloid paroxysmal activity, and a later increase of the AD length. The diphasic effect of the injection of kainic acid into the entopeduncular nucleus is likely due to the structural analogy of this drug with a neuroexcitant amino acid, monosodium glutamate. The inhibitory role of the entopeduncolar nucleus on the paroxysmal phenomena evoked in the amygdala is emphasized.

In order to study the relationships between the claustrum and motor cortex neurons both of area 4 and area 6 in the cat, an experiment was performed in which the effect of claustral stimulation on pyramidal tract neurons was investigated. Single shock electrical activation of the claustrum caused an inhibition of the spontaneous activity of the neurons, or an inhibition preceded by short activation, or no effect. These evidences lead to the conclusion that the claustrum exerts a role in movement organization.

The effects of substantia nigra stimulation on the rage reaction evoked by hypothalamic activation were studied. The reference value of the rage reaction was the latency of the hissing, which was constant in all animals when hypothalamic stimulation was performed with the same parameters. Simultaneous activation of substantia nigra and hypothalamus determined a significant decrease of the hissing latency. The influence of the substantia nigra on the affective components of the aggressive behaviour in underlined.