Lp. Solanoflores et al., NEURONAL REGENERATION AND ESTROUS-CYCLE RESTORATION AFTER LOCUS COERULEUS-PERIVENTRICULAR GRAY SUBSTANCE SECTION, Brain research bulletin, 37(4), 1995, pp. 377-389
The locus coeruleus (LC) was anatomically separated from the periventr
icular gray substance (PVG) by means of knife cuts in the adult female
rat presenting regular estrous cycling. This resulted in a transient
suppression of the estrous cycling that lasted 10-13 days after surger
y, After this period, irregular or regular cycling activity was observ
ed. The regular cycling was restored 30-45 days after the knife cuts.
Golgi impregnation of some of the brains of these rats revealed regene
rative elements in the knife-cut-insulted area. Thus, blood vessels, m
acrophagic-like elements, and glial-like elements were observed in clo
se relation with the knife-cut pathway. Additionally, well-defined sta
ined neurons typical of the LC and PVG were observed in close proximit
y to the knife-cut pathway. Dendritic and axon projections towards the
insulted area were observed. Well defined axons were seen across the
knife-cut pathway. These data support, first, that the LC-PVG communic
ation is part of a circuitry for the modulation of gonadotropic activi
ty, and second, that in the restoration of the estrous cyclicity after
the knife cut, regenerative processes leading to a LC-PVG functional
reconnection occurred after the knife cut.