Chronic Fluoxetine Treatment Suppresses Plasticity (Long-Term Potentiation) in the Mature Rodent Primary Auditory Cortex In Vivo
Figure 2
(a) Schematic diagram of electrode placements in the medial geniculate nucleus (MGN) and primary auditory cortex (A1); numbers indicate distance (in mm) from bregma. Diagrams adapted from Paxinos and Watson [40]. (b) Field postsynaptic potentials (fPSPs) recorded in A1 in response to single pulse MGN stimulation consisted of two successive, negative-going peaks. (the initial, sharp, negative spike is the stimulation artifact.) Red and blue traces are taken before and after theta-burst stimulation of the MGN, respectively. Note the absence of clear potentiation of the second fPSP peak in the fluoxetine-treated rat. (c) Final urethane dose required for anesthesia induction in the two treatment groups. (d) Stimulation intensities used for the electrophysiological experiments. (e) Baseline (pre-LTP induction) amplitude of the first fPSP peak. (f) The second fPSP peak recorded in A1 of rats given access to drinking water () or water containing fluoxetine (0.2 mg/mL; ) during a 4-week treatment period. Statistical analyses for all comparisons did not reveal any significant group differences. (’s ; note that the 23% amplitude increase for the second fPSP peak in fluoxetine animals also failed to approach statistical significance, .)
