Neurons controlling cardiovascular responses to emotion are located in lateral hypothalamus-perifornical region

Abstract

We did four experiments to determine whether the lateral hypothalamus-perifornical (LH/PF) region is the source of neuronal cell bodies responsible for producing the cardiovascular (CV) responses associated with emotion or the defense reaction. Of particular concern was whether the paraventricular nucleus (PVN) plays a role in the generation of these CV responses. Mapping the hypothalamus with electrical stimulation showed that the CV pattern of responses was never produced by stimulating the PVN and was invariably produced by stimulating the LH/PF region. Complete electrolytic destruction of the PVN and subsequent axonal degeneration did not change the CV pattern of responses elicited by LH/PF stimulation, whereas any encroachment of the lesion on the LH/PF region decreased the magnitude of the CV responses. Injection of the neuroexcitotoxin ibotenic acid (Ibo) into the PVN did not affect responses to LH/PF stimulation, whereas Ibo injection into the LH/PF region eliminated or severely attenuated the CV responses. Retrograde labeling of cells from the thoracic cord and the ventrolateral reticular formation revealed a scattered group of cells in the LH/PF region that may be the cells controlling the CV responses. These results point directly to the LH/PF region as the source of the cell bodies responsible for the autonomic responses associated with emotion or defense reactions.

Neural dynamics underlying impaired autonomic and conditioned responses following amygdala and orbitofrontal lesions.

“…This second mechanism of FSS can explain the observation that the kind of FSS that is assessed by actual consumption rather than by CS preference remains intact even after ORB l and AMYG lesions (Hatfield et al, 1996;Dunn and Everitt, 1988 (Braesicke, et al 2005). This influence is relayed from the hypothalamus to cardiovascular regulatory neurons in the medulla (Smith et al, 1990;Nakamura et al, 1992;Zhang et al, 2005Zhang et al, , 2006. The component of the blood pressure variable attributable to appetitive or aversive stimuli, B, is calculated as follows: …”

Corticotropin-Releasing Factor Induces Differential Behavioral and Cardiovascular Effects after Intracerebroventricular and Lateral Hypothalamic/Perifornical Injections in Rats

“…The often controversial results regarding the magnitude and direction of effects are due to a site specificity and difference in methodology [17]. The LH/PFx region seems to be involved in the cardiovascular responses ac companying emotional behavior [39]. Destruction of the LH/PFx region has been shown to abolish cardiovascular but not behavioral responses associated with emotion [26,39], thus pointing to a dissociation of the various levels of the stress response each of which may involve different mechanisms of action in terms of signalling pathways (cir cuitry) and compounds (neurotransmitters and -pep tides).…”

Neuromodulatory Basis of Emotion

“…These regions project to a specific region of the hypothalamus (defined as comprising the perifornical region and the medial portion of the lateral hypothalamus) which was consequently termed HACER (Hypothalamic Area Controlling Emotional Responses). Efferents of the HACER have in turn been identified (32) and share the common property of sending relatively direct inputs to the intermediolateral column cells of the thoracic cord (major group of autonomic cells) (33). Other studies further suggested that the hypothalamic paraventricular nucleus contained separate but interacting populations of cells mediating differentially autonomic and endocrine responses, making of this nucleus a locus of endocrine and autonomic integration (34).…”