Neurochemical transmission of baroreceptor input in the nucleus tractus solitarius

Baroreceptor activation has been found to produce different types of discha rge patterns in neurons in the nucleus tractus solitarius (NTS). The contri bution of different glutamate receptor subtypes, neuropeptide modulators an d input from different baroreceptor subtypes to the generation of firing pa tterns in NTS barosensitive neurons was examined in a series of studies. Re sults from these studies indicate that both subtypes of ionotropic glutamat e receptors contribute to discharge in barosensitive neurons, and the role of each subtype can vary for different neurons. The neuropeptide neurotensi n was found to modulate baroreceptor control of BP and discharge of central barosensitive neurons, both through modulation of baroreceptor afferent in put and possibly through release of neurotensin by baroreceptor afferent fi bers in the NTS. Finally, selective modulation of input from baroreceptor s ubtypes indicates that there is some degree of divergent baroreceptor inner vation of NTS neurons that could contribute to initiation of their differen t discharge patterns in response to baroreceptor input. (C) 2000 Elsevier S cience Inc.