Fig. 4.

Proposed interaction between arterial baroreceptor afferents, exercise pressor reflex (EPR), and PVN vasopressinergic (VP) pathways that project to second-order neurons within the NTS. During exercise, both EPR (through a GABAergic projection) and VP (through an axo-axonal inhibitory synapse) partially inhibit afferent signaling by baroreceptors, thus limiting the degree of baroinhibition of the heart during pressure increases. These exercise-induced effects instantaneously reset baroreflex function (left). Blue, excitatory glutamatergic pathways; orange, GABAergic inhibitory pathways; pink, descending vasopressinergic projections; green, parasympathetic nervous activity (PSNA); red, SNA to the heart. CVLM, caudal ventrolateral medulla; RVLM, rostral ventrolateral medulla. b/min, Beats/min.