Dopamine-sensitive signaling mediators modulate psychostimulant-induced ultrasonic vocalization behavior in rats.
The mesolimbic dopamine system plays a major role in psychostimulant-induced ultrasonic vocalization (USV) behavior in rodents. Within this system, psychostimulants elevate synaptic concentrations of dopamine thereby leading to exaggerated activation of postsynaptic dopamine receptors within the D1-like and D2-like subfamilies. Dopamine receptor stimulation activate several transmembrane signaling systems and cognate intracellular mediators; downstream activation of transcription factors then conveys the information from receptor activation to appropriate modulation of cellular and physiologic functions. We previously showed that cocaine-induced USV behavior was associated with enhanced expression of the neurotrophin BDNF. Like cocaine, amphetamine also increases synaptic dopamine levels, albeit primarily through facilitating dopamine release. Therefore, in the present study we investigated whether amphetamine and cocaine similarly activate dopamine-linked signaling cascades to regulate intracellular mediators leading to induction of USV behavior. The results show that amphetamine increased the emission of 50 kHz USVs and this effect was blocked by SCH23390, a D1 receptor antagonist. Similar to cocaine, amphetamine increased BDNF protein expression in discrete brain regions, while pretreatment with K252a, a trkB neurotrophin receptor inhibitor, significantly reduced amphetamine-induced USV behavior. Inhibition of cyclic-AMP/PKA signaling with H89 or inhibition of PLC signaling with U73122 significantly blocked both the acute and subchronic amphetamine-induced USV behavior. In contrast, pharmacologic inhibition of either pathway enhanced cocaine-induced USV behavior. Although cocaine and amphetamine similarly modulate neurotrophin expression and USV, the molecular mechanisms by which these psychostimulants differentially activate dopamine receptor subtypes or other monoaminergic systems may be responsible for the distinct aspects of behavioral responses.
Department of Pharmaceutical Sciences, Notre Dame of Maryland University, School of Pharmacy, Baltimore, MD 21210, United States. Electronic address: swilliams@ndm.edu.
Stacey N
SN
Williams
School of Medicine, City University of New York, City College, 160 Convent Avenue, New York, NY 10031, United States. Electronic address: aundieh@ccny.cuny.edu.
Ashiwel S
AS
Undieh
D000661:Amphetamine / Q000008:administration & dosage / Q000494:pharmacology*; D000818:Animals; D019208:Brain-Derived Neurotrophic Factor / Q000187:drug effects*; D000697:Central Nervous System Stimulants / Q000008:administration & dosage / Q000494:pharmacology*; D003042:Cocaine / Q000008:administration & dosage / Q000494:pharmacology*; D004298:Dopamine / Q000378:metabolism*; D018765:Dopamine Uptake Inhibitors / Q000008:administration & dosage / Q000494:pharmacology*; D008297:Male; D010726:Phosphodiesterase Inhibitors / Q000494:pharmacology; D047428:Protein Kinase Inhibitors / Q000494:pharmacology; D051381:Rats; D017207:Rats, Sprague-Dawley; D020813:Receptor, trkB / Q000037:antagonists & inhibitors; D017447:Receptors, Dopamine D1 / Q000037:antagonists & inhibitors; D015398:Signal Transduction / Q000187:drug effects*; D000069453:Ultrasonic Waves; D014828:Vocalization, Animal / Q000187:drug effects*
D019208:Brain-Derived Neurotrophic Factor; D000697:Central Nervous System Stimulants; D018765:Dopamine Uptake Inhibitors; D010726:Phosphodiesterase Inhibitors; D047428:Protein Kinase Inhibitors; D017447:Receptors, Dopamine D1; D000661:Amphetamine; D020813:Receptor, trkB; D003042:Cocaine; D004298:Dopamine
Brain-derived neurotrophic factor; D1-like receptor; Dopamine; Psychostimulant; Ultrasonic vocalization; trkB receptor