Control Of Emotional Behavior Research Articles

Dopamine Function in the Prefrontal Cortex

This chapter summarizes the influence of the mesocortical dopaminergic (DA) system on the excitatory responses induced in the prefrontal cortex (PFC) following electrical stimulation of the thalamic mediodorsal nucleus (MD). The DA innervation of the PFC that originates from the ventral tegmental area (VTA) has been shown to be crucial for its functions. The particularly high reactivity of the mesocortical DA system to stressful situations or anxiogenic drugs suggests that this system is involved in the control of emotional behavior. Moreover, the DA neurotransmission in the PFC contributes to the regulation of cognitive functions. The DA- and VTA-induced inhibition of efferent PFC neurons may result from a direct action of DA on pyramidal cells and/or an indirect effect involving GABA interneurons. Several observations also support a possible involvement of CABA interneurons in the inhibitory effect of DA on pyramidal cells. Moreover, the inhibitory GABAergic postsynaptic potentials recorded in pyramidal cells are increased by DA application on PFC slices. The in vivo study also suggests that part of the inhibitory responses of PFC cells induced by the activation of the mesocortical DA system involves a local GABAergic component. Electrical stimulation of the MD evokes excitatory responses in PFC neurons that result not only from the activation of the MD-PFC pathways, but also from the activation of recurrent collaterals of the antidromically driven PFC fibers projecting to the MD. The mesocortical DA system exerts a potent inhibitory control on the excitatory responses induced by the activation of intracortical recurrent collaterals of the PFC pyramidal cells that project to the MD. The complex but specific influence of DA on the transfer of information may explain the major role of the mesocortical DA system in the functions of the PFC.

Habituation of acoustic startle in rats--a functional ablation study.

Data from lesion studies data indicate that the removal of the medial cerebellum prevents acquisition but not retention of long-term habituation (LTH) of the acoustic startle response (ASR). The spreading depression (SD) of the vermis was used to examine under more functional conditions the build-up of LTH of the ASR in Wistar rats. Our findings showed that reversible blockade of the vermis during training disrupted LTH of the ASR without changing within-trials habituation. In contrast to previous data, the present results suggest that SD strongly affects the amplitude of the startle response. The data are discussed in respect to a role of the vermis in the control of emotional behaviour in animals.

Control of emotional behaviour through the hypothalamus and amygdaloid complex.

Control of emotional behaviour through the hypothalamus and amygdaloid complex.

Effect of LSD-25 on the septal region of the rat brain.

STIMULATION studies have suggested that the septal region1,2 of many mammals affects behavioural reactions. In rats bilateral lesions of the septal nuclei produce an acute typical reaction resembling aggression which lasts from 24 to 48 h3. Septal hyper-irritability after electrical stimulation has been reported to last from 7 to 14 days3. Amygdaloid lesions appear to inhibit the septal reaction in the rat and it is believed that these two structures may have opposite functions in the control of emotional behaviour, at least in rats4.