TY - JOUR T1 - Intraperiaqueductal gray glycine and D-serine exert dual effects on rostral ventromedial medulla ON- and OFF-cell activity and thermoceptive threshold in the rat. AU - Palazzo,Enza, AU - Guida,Francesca, AU - Migliozzi,Annalucia, AU - Gatta,Luisa, AU - Marabese,Ida, AU - Luongo,Livio, AU - Rossi,Claudia, AU - de Novellis,Vito, AU - Fernández-Sánchez,Enrique, AU - Soukupova,Marie, AU - Zafra,Francisco, AU - Maione,Sabatino, Y1 - 2009/09/23/ PY - 2009/9/25/entrez PY - 2009/9/25/pubmed PY - 2010/2/23/medline SP - 3169 EP - 79 JF - Journal of neurophysiology JO - J Neurophysiol VL - 102 IS - 6 N2 - We have studied the involvement of the N-methyl-D-aspartate receptor (NMDAR) glycine site and the strychnine-sensitive glycine receptor (GlyR) in the ventrolateral periaqueductal gray (VL-PAG) on nociceptive behavior (tail flick) and pain-related changes on neuronal activity in the rostral ventromedial medulla (RVM). Glycine or D-serine increased the tail-flick latency, reduced OFF-cell pause, and delayed its onset and increased the time between the onset of the OFF-cell pause and the tail withdrawal. Conversely, they decreased the ongoing activity of the ON cell, the tail-flick-induced ON-cell firing, whereas they delayed the onset of increased tail-flick-induced ON-cell firing. Also, glycine or D-serine reduced the interval between the onset of the increased ON-cell firing and tail withdrawal. Whereas 7-Cl-kynurenic acid (7-Cl-KYN) prevented such effects, strychnine did not do so. A higher dose of 7-Cl-KYN or strychnine was per se able to reduce or increase tail-flick latency and increase or reduce ON-cell activities, respectively. A higher dose of glycine was hyperalgesic in the presence of 7-Cl-KYN, whereas such an effect was prevented by strychnine. These data suggest 1) a dual role of glycine in producing hyperalgesia or analgesia by stimulating the GlyR or the NMDARs within the VL-PAG, respectively; 2) consistently that RVM ON and OFF cells display opposite firing patterns to the stimulation of the VL-PAG NMDAR glycine site and GlyR activation; and 3) a tonic role of these receptors within the VL-PAG-RVM antinociceptive descending pathway. SN - 1522-1598 UR - https://www.unboundmedicine.com/medline/citation/19776366/Intraperiaqueductal_gray_glycine_and_D_serine_exert_dual_effects_on_rostral_ventromedial_medulla_ON__and_OFF_cell_activity_and_thermoceptive_threshold_in_the_rat_ L2 - https://journals.physiology.org/doi/10.1152/jn.00124.2009?url_ver=Z39.88-2003&rfr_id=ori:rid:crossref.org&rfr_dat=cr_pub=pubmed DB - PRIME DP - Unbound Medicine ER -