Biomedical subjects

H E Siegel

Publications and source records attributed to H E Siegel.

7 recordsLinked to original sources

PubMed1986

Regulation of feline aggression by the bed nucleus of stria terminalis.

The purpose of this experiment was to study the possible modulatory role of the bed nucleus of stria terminalis (BNST) in the regulation of affective defense and quiet biting attack reactions in the cat. The experimental paradigm employed concurrent electrical stimulation of the hypothalamic attack sites and of the BNST. The results of the present study demonstrate that concurrent electrical stimulation of the BNST can differentially modulate the two different forms of aggressive behavior by facilitating affective defense and by suppressing quiet biting attack.

Aggression↗

PubMed1985

A [14C]2-deoxyglucose analysis of the functional neural pathways of the limbic forebrain in the rat. V. The septal area.

The [14C]2-deoxyglucose (2-DG) metabolic mapping technique has been used to identify the regions responding with an augmented rate of metabolism following focal electrical stimulation of various sites within the lateral septal nucleus and medial septal nucleus/diagonal band (MSN/DB) complex in the rat. Since 2-DG uptake has been correlated with rates of functional activity, it was the intention of this study to suggest the anatomical substrates underlying various physiological and behavioral responses elicited by stimulation of the septal area. The results show that stimulation of any region within the lateral septal nucleus produced a profound bilateral activation of both the lateral septal nucleus, as well as the hippocampal formation. While stimulation of a number of different fiber systems associated with the lateral septum could contribute to the observed pattern of labeling, the data suggest that, functionally, a major consequence of such stimulation is the antidromic activation of CA3----lateral septum fibers to axonal branch points, beyond which, orthodromic propagation of the impulse produces activation in CA3 target regions, including subfields CA1 and CA3, as well as the lateral septal nucleus, bilaterally. In addition, regions typically manifesting metabolic activation following stimulation of the lateral septal nucleus included the ipsilateral diagonal band of Broca, nucleus accumbens, lateral preoptic area and lateral hypothalamus, posteriorly, and the prelimbic cortex, anteriorly. Occasionally, target regions of the postcommissural fornix, including the medial mammillary nucleus and anterior thalamic nuclei were also activated following stimulation of the lateral septal nucleus. In contrast to the widespread pattern of activation resulting from stimulation of the lateral septal nucleus, stimulation of the MSN/DB complex produced activation which was largely confined to the medial forebrain bundle. In a final phase of the experiment, afterdischarge activity was elicited by sodium penicillin injection into the lateral septal nucleus. Such treatment produced more widespread 2-DG uptake, including more extensive activation within the lateral septal nucleus, hippocampal formation, amygdala, and thalamus. Additionally, the prefrontal cortex and temporal neocortex were activated.

Animals↗

PubMed1985

Topographically organized midbrain modulation of predatory and defensive aggression in the cat.

Hypothalamic sites from which quiet biting attack and affective defense were elicited, were concurrently stimulated with others in the midbrain from which modulation of these behaviors was attempted. Stimulation of medial and lateral aspects of the tegmentum differentially modulated quiet biting attack and affective defense behavior. Facilitation of quiet attack and suppression of affective defense resulted from stimulation of the lateral tegmentum, while suppression of quiet attack and facilitation of affective defense followed stimulation of its medial aspect.

Aggression↗

PubMed1985

Forebrain structures regulating flight behavior in the cat.

The present study was conducted to determine the role of the bed nucleus of the stria terminalis (BNST) and preoptic region in the regulation of hypothalamically elicited flight behavior in the cat. The general paradigm involved concurrent electrical stimulation of sites in the hypothalamus from which flight responses were elicited and of the BNST or preoptic region from which modulation of flight behavior was attempted. Electrical stimulation of the dorsal and ventral preoptic region modulated flight behavior in opposing ways. Suppression of flight behavior resulted from stimulation of the BNST and ventral aspect of the preoptic region, while facilitation of the behavioral response followed stimulation of the dorsal aspect of the preoptic region.

Animals↗

PubMed1984

An analysis of the mechanisms underlying septal area control of hypothalamically elicited aggression in the cat.

This experiment was performed in order to examine several of the underlying mechanisms by which the septal area and adjacent regions regulate quiet biting attack behavior elicited from electrical stimulation of the hypothalamus in the cat. The results clearly indicate that stimulation of the septal area and anterior cingulate gyrus increased the latency for the occurrence of quiet biting attack behavior. Those sites within the septal area from which inhibition of attack can be produced are linked to sensory mechanisms associated with trigeminal reflexes activated during hypothalamic stimulation. Stimulation of these septal area sites decreased the lateral extent of the 'effective sensory fields' of the lipline established during hypothalamic stimulation, but did not appear to have any affect upon the latency of the hypothalamically elicited jaw-opening response. Deoxyglucose autoradiography revealed that the inhibition resulting from stimulation of the lateral septal area may be due to either the monosynaptic activation of the lateral hypothalamus or the disynaptic activation of this area utilizing a circuit involving the nuclei of the diagonal band of Broca.

Aggression↗

PubMed1984

A [14C]2-deoxyglucose analysis of the functional neural pathways of the limbic forebrain in the rat. IV. A pathway from the prefrontal cortical-medial thalamic system to the hypothalamus.

The present study utilized the [14C]2-deoxyglucose (2-DG) cell labeling procedure to characterize a functional pathway from the prefrontal cortex (Pfc) and mediodorsal thalamic nucleus (MD) to the hypothalamus. Rats were injected with 2-DG prior to a 45 min experimental paradigm consisting of alternating 30 s on-off periods of electrical brain stimulation. Standard procedures were utilized for the removal and processing of brain tissue for X-ray autoradiography. In the first phase of this study, stimulation applied to the prefrontal cortex generally yielded a pattern of 2-DG distribution consistent with the findings of classical anatomical studies. Stimulation of the dorsomedial and ventromedial prefrontal cortex or the infralimbic cortex produced the most effective activation of the diencephalon. This activation was primarily limited to MD, with no involvement of any region of the hypothalamus. In the second phase of this study, brain regions activated following stimulation of sites along the rostro-caudal axis of MD were examined. Stimulation of MD resulted in the activation of the nucleus reuniens and other midline and non-specific thalamic nuclei. Stimulation of this nucleus also activated the ventromedial thalamic nucleus, medial aspects of the nucleus accumbens and the medial and sulcal prefrontal cortices. Again, in each of these cases, labeling within any region of the hypothalamus could not be detected. Since MD stimulation activated the midline thalamus, and the nucleus reuniens in particular, the last phase of this experiment involved stimulation of the nucleus reuniens in order to determine the source of medial thalamic inputs to the hypothalamus. Stimulation of the nucleus reuniens activated fibers which were distributed to both the medial and lateral hypothalamus. In addition, stimulation also activated the descending periventricular system, which could be followed to the level of the midbrain central gray and such limbic structures as the hippocampal formation, septal area, amygdala and prefrontal cortex. These findings indicate that Pfc-MD activation of the hypothalamus is achieved indirectly via interneurons within the nucleus reuniens.

Animals↗

PubMed1984

Differential control of aggression by the midbrain.

Electrical stimulation of the midbrain tegmentum can produce differential modulation of quiet biting attack and affective defense behavior elicited from the hypothalamus of the cat. Stimulation of the lateral half of the tegmentum facilitated quiet biting attack and suppressed affective defense. Conversely, stimulation of the medial tegmentum suppressed quiet biting attack and facilitated affective defense. These results clearly indicate a topographic organization of modulatory sites controlling hypothalamic aggression within the midbrain tegmentum.

Affect↗