Nucleus accumbens lesions

D2 Mostly in striatum, nucleus accumbens and olfactory tubercle but also on neuron cell bodies in substantia nigra and ventral tegmentum where they are the autoreceptors for locally (dendritic) released DA. The loss of specific D2 antagonist binding in the striatum after lesions of the afferent nigro-striatal tract indicates their presynaptic autoreceptor role on terminals there. Other lesion studies have also established D2 receptors on other inputs such as the cortico striatal tract. 

The injection of 6-OHDA into the rat nucleus accumbens produces the expected proliferation of DA receptors and resulting supersensitivity so that doses of apomorphine lower than normal produce a significant attenuation of PPI. This is not seen after the production of supersensitivity by toxin lesions of the substantia nigra and prefrontal cortex. The effects of amphetamine were also mainly modified by accumbens lesions. Thus as DA agonists primarily augment the positive symptoms such findings link these with the accumbens. 

FIGURE 1. Effects of amphetamine, scopolamine, caffeine, and saline on locomotor activity in rats with 6-OHDA lesions of the nucleus accumbens or sham-operated controls (n=8 rats/group)... 

FIGURE 2. Effects of 6-OHDA lesions of the nucleus accumbens on the... 

Biochemical analyses of 6-OHDA-injected animals revealed a 93 percent depletion of dopamine. The tissue was assayed using electrochemical detection following separation by high-pressure liquid chromatography (Felice et al. 1978). recorded as ng/mg protein in the nucleus accumbens and compared to control rats with sham lesions (sham=65.5 4.4, lesion=4.9 1.5 t(39)=23.4). A lesion was defined as complete if 75 percent or more of the dopamine was determined to be depleted from the nucleus accumbens compared to mean sham group values. 

The motor activation produced by psychomotor stimulants has been long associated with the midbrain dopamine systems. While focused stereotyped behavior produced by high doses of indirect sympathomimetics is blocked by removal of dopamine terminals in the corpus striatum (Creese and Iversen 1975), the locomotor activation produced by low doses of indirect sympathomimetics is blocked by removal of dopamine terminals in the region of the nucleus accumbens (Kelly et al. 1975). This dopaminergic substrate for psychostimulant effects appears selective for the indirect sympathomimetics in that dopamine lesions to the region of the nucleus... 

You have to know that we take out most of the mesocorticolimbic dopamine system with that lesion we are not just taking out the nucleus accumbens dopamine projeetion. I am very eareful to put the region of the nucleus accumbens on my slide. 

Kelly, P.H. Seviour, P. and Iversen, S.D. Amphetamine and apomorphine response in the rat following 6-OHDA lesions of the nucleus accumbens septi and corpus striatum. Brain Res 94 507-522, 1975. 

Roberts, D.C. Koob, G.F. Klonoff, P. and Fibiger, H.C. Extinetion and recovery of cocaine self-administration following 6-hydroxydopamine lesions of the nucleus accumbens. Pharmacol Biochem Behav 12 781-787, 1980. 

French, E. Vantini, G. Contrera s, P. Pi 11 a pi 1, C. and Quirion, R. Phencyclidine (PCP) binding in the nucleus accumbens and PCP-induced hyperactivity are decreased following 60HDA lesions of the mesolimbic dopamine system. Neurosci Abst 10 1205, 1984. 

French, E.D., and Vantini, G. Phencyclidine-induced locomotor activity in the rat is blocked by 6-hydroxydopamine lesion of the nucleus accumbens Comparisons to other psycomotor stimulants. Psvchopharmacoloqy 82 83-88, 1984. 

Figure 7.5 Histograms illustrating typical behavioral state changes observed following bilateral lesions of dopaminergic ventral tegmental pathways in rats receiving 6-hydroxydopamine into the nucleus accumbens (217). Notable amounts of REM sleep are evident during both the major wake (1900-0700) and major sleep (0700-1900) periods. Maintenance of the rest and activity periods to the 12 12 h light dark schedule, respectively, demonstrates the relative preservation of circadian processes.

Zito, K.A., Vickers, G., and Roberts, D.C.S., Disruption of cocaine and heroin self-administration following kianic acid lesions of the nucleus accumbens, Pharmacol. Biochem. Behav, 23, 1029, 1985. 

Parsons LH, Smith AD, Justice JB Jr. 1991b. The in vivo microdialysis recovery of dopamine is altered independently of basal level by 6-hydroxydopamine lesions to the nucleus accumbens. J Neurosci Methods 40(2—3) 139-147. 

Blaha CD, AUen EE, Das S, Inghs WE, Latimer MP, Vincent SR, Winn P (1996) Modulation of dopamine efflux in the nucleus accumbens after cholinergic stimulation of the ventral tegmental area in intact, pedunculopontine tegmental nucleus-lesioned, and laterodorsal tegmental nucleus-lesioned rats. J Neurosci 16 714-722... 

Kelsey, John E.,and Susan R. Arnold. 1994."Lesions of the Dorsomedial Amygdala, but Not the Nucleus Accumbens, Reduce the Aversiveness of Morphine Withdrawal in Rats." Behavioral Neuroscience 108 1119-27. 

Stine CD, Lu W, Wolf ME. 2001. Expression of AMPA receptor flip and flop mRNAs in the nucleus accumbens and prefrontal cortex after neonatal ventral hippocampal lesions. Neuropsychopharmacology 24 253-266. 

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