Possible Interaction: Gamma-Aminobutyric Acid and Formalin

“The levels of GAD expression and GABA concentration decreased after formalin injection and were increased by P7C3.”

“ GABA levels in the dorsal periaqueductal gray were lower in rats receiving intraplantar injection of formalin , compared with saline-treated controls.”

“Likewise, formalin increased glutamate and produced a biphasic response on GABA.”

“Microinjection of GABA to PAG significantly increased these behavioural responses to formalin.”

“Microinjection of GABA to GiA increased the behavioural response to formalin between 10 and 20 min post‐injection, while microinjection of DLH reduced this response at all time points except 10 min post‐injection (n=8, P<0.05, Mann–Whitney U‐test).”

“Microinjection of GABA to GiA significantly increased the behavioural response to formalin from 20 to 50 min post‐injection.”

“Both glutamate and GABA release decreased after the injection of formalin during phase I and phase II of hyperalgesia.”

“However, approximately … injury by formalin, … GABA and activation of GABA(A) receptors in the spinal cord that 1) contributes to the period of quiescence between phase 1 and … diminishes the magnitude of pain behaviors in phase 2, possibly by limiting the development of central sensitization in the spinal cord.”