title: High-anxiety rats are less sensitive to the rewarding affects of amphetamine on 50kHz USV.
abstract: This study assessed behaviour, as measured by 50kHz calls related to positive affect, in rats with different fear conditioned response strengths: low-anxiety rats (LR) and high-anxiety rats (HR), after amphetamine injection in a two-injection protocol (TIPS). The results showed that the first dose of amphetamine evoked similar behavioural effects in frequency-modulated (FM) 50kHz calls in the LR and HR groups. The second injection of amphetamine resulted in stronger FM 50kHz calls in LR compared with HR rats. The biochemical data ('ex vivo' analysis) showed that the LR rats had increased basal levels of dopamine in the amygdala, and increased homovanilic acid (HVA), dopamine's main metabolite, in the amygdala and prefrontal cortex compared with HR rats. The 'in vivo' analysis (microdialysis study) showed that the LR rats had increased HVA concentrations in the basolateral amygdala in response to an aversively conditioned context. Research has suggested that differences in dopaminergic system activity in the amygdala and prefrontal cortex may be one of the biological factors that underlie individual differences in response to fear stimuli, which may also affect the rewarding effects of amphetamine.
authors.affiliation: Department of Neurochemistry, Institute of Psychiatry and Neurology, 9 Sobieskiego Street, 02-957 Warsaw, Poland. Electronic address: lehmaipn@yahoo.co.uk.
authors.forename: Małgorzata H
authors.initials: MH
authors.lastname: Lehner
authors.affiliation: Department of Neurochemistry, Institute of Psychiatry and Neurology, 9 Sobieskiego Street, 02-957 Warsaw, Poland.
authors.forename: Ewa
authors.initials: E
authors.lastname: Taracha
authors.affiliation: Department of Neurochemistry, Institute of Psychiatry and Neurology, 9 Sobieskiego Street, 02-957 Warsaw, Poland.
authors.forename: Ewelina
authors.initials: E
authors.lastname: Kaniuga
authors.affiliation: Department of Experimental and Clinical Pharmacology, Medical University of Warsaw, ul Banacha 1b, 02-097 Warszawa, Poland.
authors.forename: Aleksandra
authors.initials: A
authors.lastname: Wisłowska-Stanek
authors.affiliation: Faculty of Biology and Earth Sciences, Department of Experimental and Clinical Pharmacology, Jagiellonian University in Krakow, 31-007 Kraków, ul. Gołębia 24, Poland.
authors.forename: Jacek
authors.initials: J
authors.lastname: Wróbel
authors.affiliation: Department of Neurochemistry, Institute of Psychiatry and Neurology, 9 Sobieskiego Street, 02-957 Warsaw, Poland.
authors.forename: Alicja
authors.initials: A
authors.lastname: Sobolewska
authors.affiliation: Department of Neurochemistry, Institute of Psychiatry and Neurology, 9 Sobieskiego Street, 02-957 Warsaw, Poland.
authors.forename: Danuta
authors.initials: D
authors.lastname: Turzyńska
authors.affiliation: Department of Neurochemistry, Institute of Psychiatry and Neurology, 9 Sobieskiego Street, 02-957 Warsaw, Poland.
authors.forename: Anna
authors.initials: A
authors.lastname: Skórzewska
authors.affiliation: Department of Neurochemistry, Institute of Psychiatry and Neurology, 9 Sobieskiego Street, 02-957 Warsaw, Poland; Department of Experimental and Clinical Pharmacology, Medical University of Warsaw, ul Banacha 1b, 02-097 Warszawa, Poland.
authors.forename: Adam
authors.initials: A
authors.lastname: Płaźnik
mesh_terms: D000661:Amphetamine / Q000494:pharmacology*; D000704:Analysis of Variance; D000818:Animals; D001007:Anxiety / Q000378:metabolism / Q000473:pathology / Q000503:physiopathology* / Q000523:psychology*; D000697:Central Nervous System Stimulants / Q000494:pharmacology*; D003213:Conditioning, Psychological / Q000187:drug effects / Q000502:physiology; D004195:Disease Models, Animal; D004298:Dopamine / Q000378:metabolism; D005239:Fear / Q000187:drug effects / Q000523:psychology; D006719:Homovanillic Acid / Q000378:metabolism; D008297:Male; D017551:Microdialysis; D017397:Prefrontal Cortex / Q000187:drug effects / Q000378:metabolism; D051381:Rats; D017208:Rats, Wistar; D012201:Reward; D014828:Vocalization, Animal / Q000187:drug effects*
chemical_list: D000697:Central Nervous System Stimulants; D000661:Amphetamine; D004298:Dopamine; D006719:Homovanillic Acid
keywords: 50kHz call; Amphetamine; Anxiety; Individual difference; Microdialysis; Two injection protocol sensitisation (TIPS)