Effect of disconnecting the orbital prefrontal cortex from the nucleus accumbens core on inter-temporal choice behaviour: A quantitative analysis
Effect of disconnecting the orbital prefrontal cortex from the nucleus accumbens core on inter-temporal choice behaviour: A quantitative analysis
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DOI：
10.1016/j.bbr.2008.03.041
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发表时间：
2008-08-22
影响因子：
2.7
通讯作者：
Deakin, J. F. W.
中科院分区：
文献类型：
--
作者：
Bezzina, G.;Body, S.;Deakin, J. F. W.
先前的实验表明，大鼠眼眶前额皮质（OPFC）或伏隔核（AcbC）的破坏会改变对两种延迟食物强化物的选择。颞间选择定量模型的应用表明，任何一种结构的损伤都增加了强化值的延迟依赖性退化（延迟折扣）；OPFC（而不是AcbC）的破坏也增加了较大强化物的相对价值。本实验考察了切断OPFC和AcbC对跨期选择的影响。大鼠接受兴奋毒素诱导的对侧OPFC和AcbC病变（断开）、前胼胝体切断（胼胝体切开术）、联合病变（断开+胼胝体切开术）或假病变。他们被训练在一个离散试验渐进延迟时间表，按杠杆a和B的蔗糖溶液。A上的响应在延迟d(A)后交付50 μ l的解决方案；B上的响应在延迟d(B)后交付100 μ l。d(B)在试验块间增加；d(A)在实验的各个阶段进行处理。估计每个阶段每个大鼠的无差异延迟d(B(50))（对应于50%选择B的d(B)值），并推导线性无差异函数d(B（50) vs. d(A)）。与假性损伤组相比，断连+胼胝体切开术组的无差异函数截距更低（意味着延迟折现率更高）；断连组表现出类似但不那么强健的效果，而胼胝体切开术组与假损伤组没有显著差异。结果表明，OPFC-AcbC连接参与食物强化物的延迟折扣，但没有证据表明OPFC-AcbC连接参与调节对强化物大小的敏感性。(C) 2008 Elsevier B.V.版权所有
Previous experiments showed that destruction of the orbital prefrontal cortex (OPFC) or the nucleus accumbens core (AcbC) in rats altered choice between two delayed food reinforcers. Application of a quantitative model of inter-temporal choice suggested that lesions of either structure increased the delay-dependent degradation of reinforcer value (delay discounting); destruction of the OPFC (but not the AcbC) also increased the relative value of the larger reinforcer. This experiment examined the effect of disconnecting the OPFC from the AcbC on inter-temporal choice. Rats received excitotoxin-induced contralateral lesions of the OPFC and AcbC (disconnection), severing of the anterior corpus callosum (callosotomy), a combined lesion (disconnection+callosotomy) or sham lesions. They were trained in a discrete-trials progressive delay schedule to press levers A and B for a sucrose solution. Responses on A delivered 50 mu l of the solution after a delay d(A); responses on B delivered 100 mu l after a delay d(B). d(B) increased across blocks of trials; d(A) was manipulated across phases of the experiment. Indifference delay, d(B(50)) (value of d(B) corresponding to 50% choice of B), was estimated for each rat in each phase, and linear indifference functions (d(B(50)) vs. d(A)) were derived. The disconnection+callosotomy group showed a lower intercept of the indifference function (implying a higher rate of delay discounting) than the sham-lesioned group; the disconnection group showed a similar but less robust effect, whereas the callosotomy group did not differ significantly from the sham-lesioned group. The results suggest that OPFC-AcbC connections are involved in delay discounting of food reinforcers, but provide no evidence for an involvement of OPFC-AcbC connections in regulating sensitivity to reinforcer size. (C) 2008 Elsevier B.V. All rights reserved.