Differential acute effects of fluoxetine on frontal and auditory cortex networks in vitro.
Primary cultures of neuronal networks grown on microelectrode arrays were used to quantify acute effects of fluoxetine (Prozac) on spontaneous spike and burst activity. For frontal cortex cultures, fluoxetine showed consistent inhibitory effects and terminated activity at 10-16 microM. IC(50) mean+/-S.E. for spike rates was 5.4+/-0.7 microM (n=15). For auditory cortex cultures, fluoxetine caused excitation at 1-10 microM, initial inhibition at 15 microM, and activity cessation at 20-25 microM. The spike rate IC(50) was 15.9+/-1.0 microM (n=11). Fluoxetine did not change the action potential waveform shape. However, at high concentrations, it caused total cessation of spike activity on all channels. The inhibition caused by fluoxetine was reversible for both tissues. Based on the results, we conclude that cultures showed repeatable, concentration-dependent sensitivities to fluoxetine but demonstrated tissue-specific responses for frontal and auditory cortex networks. These responses may not be due to the interference with serotonin reuptake, but may be due to a secondary effect on ionic channels.
Department of Biological Sciences, P.O. Box 305220, University of North Texas, Denton, TX 76203, USA.
Yun
Y
Xia
Kamakshi V
KV
Gopal
Guenter W
GW
Gross
D000200:Action Potentials / Q000187:drug effects; D000818:Animals; D000831:Animals, Newborn; D001303:Auditory Cortex / Q000187:drug effects* / Q000502:physiology; D046508:Culture Techniques; D004305:Dose-Response Relationship, Drug; D005109:Extracellular Matrix / Q000502:physiology; D005473:Fluoxetine / Q000494:pharmacology*; D005625:Frontal Lobe / Q000187:drug effects* / Q000502:physiology; D051379:Mice; D008807:Mice, Inbred BALB C; D008839:Microelectrodes; D009415:Nerve Net / Q000187:drug effects* / Q000502:physiology; D016900:Neurofilament Proteins / Q000378:metabolism; D009474:Neurons / Q000187:drug effects / Q000502:physiology; D012701:Serotonin / Q000494:pharmacology; D017367:Selective Serotonin Reuptake Inhibitors / Q000494:pharmacology*; D013997:Time Factors; D017971:Tin Compounds / Q000378:metabolism
D005473:Fluoxetine; D016900:Neurofilament Proteins; D012701:Serotonin; D017367:Selective Serotonin Reuptake Inhibitors; D017971:Tin Compounds; C109984:indium tin oxide