F. Reinososuarez et al., LOCATION AND ANATOMICAL CONNECTIONS OF A PARADOXICAL SLEEP INDUCTION SITE IN THE CAT VENTRAL PONTINE TEGMENTUM, European journal of neuroscience, 6(12), 1994, pp. 1829-1836
The brainstem mechanisms for the generation of paradoxical sleep are u
nder considerable debate. Previous experiments in cats have demonstrat
ed that injections of the cholinergic agonist carbachol into the oral
pontine tegmentum elicit paradoxical sleep behaviour and its polygraph
ic correlates, The different results on the pontine structures that me
diate this effect do not agree. We report here that limited microinjec
tions of a carbachol solution into the ventral part of the oral pontin
e reticular nucleus in the cat induce, with a short latency, a dramati
c, long-lasting increase in paradoxical sleep. Moreover, neuronal trac
ing experiments show that this pontine site is connected with brain st
ructures responsible for the different bioelectric events of paradoxic
al sleep. These two facts suggest that the ventral part of the oral po
ntine reticular nucleus is a nodal link in the neuronal network underl
ying paradoxical sleep mechanisms.