ÞEndogenous opioids are present in many
brainstem nuclei implicated
in the regulation of sympathetic tone and arterial pressure.
ÞThe rostral ventrolateral medulla (RVL)
provides the main descending
excitatory drive to sympathetic preganglionic neurons.
ÞThere is anatomical and
electrophysiological evidence that enkephalin is a putative neurotransmitter controlling the excitability of RVL neurons.
ÞInvestigate the postsynaptic actions of
met-enkephalin on identified
C1 and non-C1 bulbospinal RVL neurons.
ÞDetermine the pharmacological properties
of synaptic input to RVL
neurons and examine whether opioid agonists could modulate transmitter release.