S. Roder et J. Ciriello, CONTRIBUTION OF BED NUCLEUS OF THE STRIA TERMINALIS TO THE CARDIOVASCULAR-RESPONSES ELICITED BY STIMULATION OF THE AMYGDALA, Journal of the autonomic nervous system, 45(1), 1993, pp. 61-75
Anatomical and physiological studies were done in the rat to investiga
te the possibility that the cardiovascular responses elicited by stimu
lation of central nucleus of the amygdala (ACe) were mediated via proj
ections to bed nucleus of the stria terminalis (BST). In the first ser
ies, to determine the distribution of neurons in ACe that projected to
the cardiovascular region of BST, the retrograde tracer Fluorogold (F
G) or rhodamine latex micro-beads (Rd) were injected into BST. FG and
Rd injections that overlapped the cardiovascular region of BST resulte
d in retrogradely labelled neurons throughout the amygdala. In ACe, re
trogradely labelled neurons were observed primarily in the lateral sub
division of the rostral ACe compared to the caudal ACe. The medial sub
division of ACe was found to have very few retrogradely labelled neuro
ns. In the second series, the effect of either blocking synaptic trans
mission in BST with CoCl2, chemical lesions of BST with ibotenic acid
(IBO), or electrolytic lesions of BST on the depressor response elicit
ed by either electrical or chemical stimulation of ACe was investigate
d in the chloralose-anesthetized, artificially ventilated and paralyse
d rat. Microinjections of CoCl2 into BST significantly attenuated the
depressor responses to stimulation of the rostral components of the la
teral subnucleus of ACe, but not those to stimulation of the caudal an
d medial components of ACe. Microinjections of IBO into BST or electro
lytic lesions of BST resulted in similar effects on the depressor resp
onses to ACe stimulation. Taken together, these data indicate that neu
rons within the rostral components of the lateral subnucleus of ACe pr
oject to the cardiovascular region of BST and mediate in part the depr
essor responses to stimulation of the rostral ACe. On the other hand,
the depressor responses elicited from the caudal ACe are not mediated
through BST. These results suggest that at least two independent pathw
ays originate in the ACe that influence the circulation.