Benzodiazepine receptors in the periaqueductal grey mediate anti-aversive drug action

Alprazolam potentiates the antiaversive effect induced by the activation of 5-HT1A and 5-HT2A receptors in the rat dorsal periaqueductal gray

“…As consistently reported in the literature, our results showed that intra-DPAG injection of 8-OH-DPAT, DOI, and midazolam increased the amount of current that needed to be applied to the DPAG to evoke an escape response (Audi and Graeff 1984;Nogueira and Graeff 1995). This result is suggestive of a panicolytic-like effect.…”

“…Therefore, in each of the systemically injected groups, animals served as their own controls for the central effects of the drugs. The doses of the 5-HT agonists and midazolam were selected on the basis of previous results showing their inhibitory effect on DPAG-evoked escape responses (Audi and Graeff 1984;Jacob et al 2002;Jenck et al 1998;Nogueira and Graeff 1995;Schütz et al 1985).…”

Serotonin-2A receptor regulation of panic-like behavior in the rat dorsal periaqueductal gray matter: the role of GABA

“…In light of evidence discussed above, the results obtained here with bicuculline give clear support to the proposal (Nogueira and Graeff 1995) that facilitation of GABAmediated neurotransmission in the dPAG accounts for the panicolytic-like effect resulting from the activation of 5-HT2A receptors in the same brain area. In line with this assumption, direct intra-dPAG administration of GABA-enhancing drugs such as the GABAA receptor agonist muscimol or the benzodiazepine receptor agonist midazolam also inhibits escape expression in the experimental model currently employed (Audi and Graeff 1984;Graeff et al 1986).…”

Benzodiazepine receptor and serotonin 2A receptor modulate the aversive-like effects of nitric oxide in the dorsolateral periaqueductal gray of rats

“…The solutions were prepared immediately before use and were kept on ice and protected from the light during the experimental session. The doses were based on previously reported dose-response curves of the effects of these drugs administered into the dlPAG (Audi and Graeff 1984;Nogueira and Graeff 1995;De Oliveira et al 2001). …”

“…Local injection of drugs that enhance or mimic gamma-aminobutyric acid (GABA)-mediated neurotransmission, such as benzodiazepines (BZs), inhibits the escape behavior induced by dlPAG electrical stimulation (Audi and Graeff 1984). Serotonin (5-HT) may also modulate aversion in this structure.…”