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INVOLVEMENT OF PRELIMBIC BUT NOT INFRALIMBIC CORTEX ON THE PRESSOR RESPONSE TO CHEMOREFLEX ACTIVATION IN UNANESTHETIZED RATS
Author(s) -
Granjeiro Érica Maria,
Scopinho América,
Aguiar Corrêa Fernando Morgan,
Resstel Leonardo Barbosa
Publication year - 2010
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.24.1_supplement.lb534
Subject(s) - infralimbic cortex , neurotransmission , microinjections , reflex , chemistry , neuroscience , medicine , endocrinology , reflex bradycardia , prefrontal cortex , heart rate , bradycardia , anesthesia , central nervous system , psychology , receptor , blood pressure , cognition
AND OBJECTIVES The ventral portion medial prefrontal cortex (vMPFC) comprises the prelimbic cortex (PL) and the infralimbic cortex (IL). It has been reported an important role of vMPFC on cardiovascular reflexes modulation. However, there is no study showing the role of this area on cardiovascular responses to chemoreflex activation. We report here a comparison between the effects of pharmacological inhibition of PL or IL neurotransmission on the pressor and bradycardic responses to chemoreflex activation evoked by KCN, i.v. administration. RESULTS AND CONCLUSION Bilateral microinjections of 200 nl of the unspecific synaptic blocker CoCl(2) (1 mM) into the PL significantly reduced the pressor (60 ± 3 vs 44 ± 3 mmHg, n=9, p<0.01) but had not effect on the magnitude of bradycardic response to chemoreflex activation (−219 ± 24 vs −201 ± 16 bpm, n=9, p>0.05). However, when local synapses in the IL were inhibited by bilateral injections of CoCl(2) into that area, no significant changes were observed on cardiovascular responses evoked by chemoreflex (n=6, p>0.05). These data indicate the involvement of the vMPFC PL area in modulation of the pressor response induced by chemoreflex activation but not in the decrease in heart rate evoked by this reflex. They also suggest that the neurons located on PL area do not play a major role in the neurotransmission of the autonomic responses to chemoreflex activation.