Microinfusion of Bupropion Inhibits Putative GABAergic Neuronal Activity of the Ventral Tegmental Area
نویسندگان
چکیده
INTRODUCTION The most common interpretation for the mechanisms of antidepression is the increase of the brain monoamine levels such as dopamine (DA). The increase of DA can reduce depression but it can also decrease the monoamine release because of autoreceptor inhibition. Although bupropion can decrease the dopamine release, there is evidence about stimulatory effects of chronic application of bupropion on ventral tegmental area (VTA) neurons. In this study, the intra-VTA acute microinfusion of bupropion on putative VTA non-Dopaminergic (VTA-nonDA) neuronal firing rates was evaluated by a single neuron recording technique. METHODS Animals were divided into 7 groups (sham, and 6 bupropion-microinfused groups with 1, 10(-1), 10(-2), 10(-3), 10(-4), and 10(-5) mol, 1 µl/3 min, intra-VTA). A single neuron recording technique was done according to the stereotaxic coordination. After 10 min baseline recording, ACSF or bupropion was microinfused. The recording continued to recovery period in the treated groups. The prestimulus time (PST) and interspike interval (ISI) histograms were calculated for every single unit. The assessment of the drug effect was carried out by one-way analysis of variance (ANOVA) and Post-hoc test. RESULTS 126 non-DA neurons were separated. Bupropion could inhibit 116 neurons and 11 neurons had no significant response. Maximum inhibition was 79.1% of baseline firing rate with 44.3 min duration. The inhibitory effect of bupropion was dose-dependent. DISCUSSION The acute inhibitory effects of bupropion on VTA-nonDA neurons can explain the fast inhibitory effects of bupropion and other antidepressants on the VTA. These data can explain some side effects of antidepressants.
منابع مشابه
Microinfusion of Bupropion Inhibits Putative GABAergic Neuronal Activity of the Ventral Tegmental Area
Introduction: The most common interpretation for the mechanisms of antidepression is the increase of the brain monoamine levels such as dopamine (DA). The increase of DA can reduce depression but it can also decrease the monoamine release because of autoreceptor inhibition. Although bupropion can decrease the dopamine release, there is evidence about stimulatory effects of chronic application o...
متن کاملThe Response of Ventral Tegmental Area Dopaminergic Neurons to Bupropion: Excitation or Inhibition?
Introduction: Antidepressants can modulate brain monoamines by acting on pre-synaptic and postsynaptic receptors. Autoreceptors can reduce the monoamines effect on the somatodendritic or pre-synaptic regions despite its postsynaptic counter effects. The direct effect of some antidepressants is related to its temporal and spatial bioavailability in the vicinity of these receptors (still a matter...
متن کاملFunctional Interaction between the Shell Sub-Region of the Nucleus Accumbens and the Ventral Tegmental Area in Response to Morphine: an Electrophysiological Study
This study has examined the functional importance of nucleus accumbens (NAc)-ventral tegmental area (VTA) interactions. As it is known, this interaction is important in associative reward processes. Under urethane anesthesia, extracellular single unit recordings of the shell sub-region of the nucleus accumbens (NAcSh) neurons were employed to determine the functional contributions of the VTA to...
متن کاملEvaluation of GABA Receptors of Ventral Tegmental Area in Cardiovascular Responses in Rat
Background: The ventral tegmental area (VTA) is well known for its role in cardiovascular control. It is demonstrated that about 20-30% of the VTA neurons are GABAergic though their role in cardiovascular control is not yet understood. This study is carried out to find the effects of GABA A and GABA B receptors on cardiovascular response of the VTA. Methods: Experiments were performed on uretha...
متن کاملVentral Tegmental Area Microinjected-SKF38393 Increases Regular Chow Intake in 18 Hours Food Deprived Rats
Ventral tegmental area (VTA) dopamine neurons play an important role in reward mechanisms of food intake, and VTA dopamine receptors exist on the terminal of glutamatergic and GABAergic neurons and regulate GABA and glutamate release. To our knowledge, there is no evidence to show that VTA D1 dopamine receptors play a role in regular chow intake. In this paper, the effect of SKF38393, a D1 rece...
متن کامل