RT Conference Proceedings
T1 Does the midbrain dorsolateral periaqueductal grey have direct connections with the pontine A5 region? A neuropharmacologic and electrophysiological study
A1 González-García, Marta
A1 López-González, Manuel Víctor
A1 Díaz-Casares, Amelia
A1 Peinado-Aragonés, Carlos Antonio
A1 Barbancho-Fernández, Miguel Ángel
A1 Dawid-Milner, Marc Stefan
K1 Neurociencias - Congresos
AB This study has been performed in spontaneously breathing anesthetised rats. We have analysed the possible interactions between the midbrain dorsolateral periaqueductal grey matter (dlPAG) and the pontine A5 region. Electrical stimulations of the dlPAG (1 ms pulses, 20-30 μA given at 100 Hz for 5s) were elicited and the evoked cardiorespiratory changes were analysed before and after ipsilateral blockade of the neurotransmission within the A5 region by means of microinjections of muscimol (50 nl, 0.25 nmol, 5s). Electrical stimulations evoked the classical “defence response” characterized by tachipnoea, hypertension and tachycardia. Tachipnoea consisted of an inspiratory facilitatory response [increase in respiratory rate (p<0.001) due to a decrease in expiratory time (p<0.01)] and was accompanied by a pressor (p<0.001) and tachycardic (p<0.001) response. Muscimol microinjected within the A5 region reduced pressor (p<0.05), tachycardic (p<0.001) and tachypnoeic (p<0.001) responses evoked to dlPAG electrical stimulations. Finally, in order to assess functional interactions between A5 and dlPAG, extracellular recordings of 40 putative A5 cells during dlPAG electrical stimulation were recorded. 16 cells were affected by dlPAG stimulation (40%). 3 cells showed orthodromic activation (14.2 ± 1.7 ms). 5 cells were excited (10.1 ± 1.6 ms). 7 cells decreased spontaneous activity to dlPAG stimulation. 24 cells were not modified by dlPAG stimulation (2 presented a respiratory pattern and 1 presented a cardiovascular pattern).   These results contribute with new data on the role of the A5 region neurones in the modulation of the cardiorespiratory response evoked on dlPAG stimulation.
YR 2018
FD 2018-07-16
LK https://hdl.handle.net/10630/16277
UL https://hdl.handle.net/10630/16277
LA eng
NO Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech
DS RIUMA. Repositorio Institucional de la Universidad de Málaga
RD 5 mar 2026