NEURONAL CONNECTIONS AND RESPONSES IN CINGULATE CORTEX

前扣带回皮质已被牵涉到情感性 对伤害性刺激的反应含有阿片合成神经元 并且具有高密度的Mu和Delta阿片受体。它不是 知道哪些神经元突起与阿片受体配体结合。这个 目前的实验将采用实验定位 由P.I.开发的定位轴突和 树突状M胆碱受体亚型。整体而言 将对大鼠进行三种损伤之一的切片分析 脑内MU和Delta型选择性配体结合分析 在冰冻切片中，盖玻片放射自显影和单个 前扣带回皮质颗粒计数：1)全深度或 层状鹅膏酸，2)选择性破坏皮质 注射免疫毒素OX7-ss后的投射神经元 皂苷进入尾状核或中脑导水管周围灰质核或进入 后扣带回，3)去传入下切病变。 第二种定位方法将涉及尾状核的预标记， 中脑导水管周围灰质或皮质投射神经元具有稳定的， 逆行运输的荧光染料。皮质神经元将 然后用酶法和机械法解离并检测 β-呋喃甲氨喋呤与预标记物锥体的MU选择性结合 神经元和未标记的锥体和多极神经元。另一个 一系列实验将评估大脑皮层中的Mu和Delta位置 日本血吸虫冰冻切片中的亚胺和丘脑亚核 兔子和人类的大脑。作为一些丘脑和大脑皮层 连接可能涉及到感觉运动方面的 对有害刺激的反应，多标签连接研究是 还建议分析丘脑皮质和皮质 兔扣带回皮质的联系。对丘脑的研究将 强调外侧巨细胞核，因为它的连接 没有被描述，也不知道它存在于任何其他 哺乳动物。大脑皮层水平的研究将侧重于地形 扣带回与视觉、扣带回之间的关系 区域。 这些研究的主要目标是阐明一种直接的方法，通过 哪种阿片剂和阿片类化合物会影响皮层神经元 自主和躯体运动中心的项目，表征 阿片受体在大鼠树突和体细胞上的分布 锥体投射神经元和多极中间神经元 描述兔体内一个几乎未知的核团的联系 丘脑。分离的成年皮层神经元可以在未来使用 评价阿片类药物上下调节机制的研究进展 受体以及阿片类化合物对离子通道的门控作用。

Anterior cingulate cortex has been implicated in affective responses to noxious stimuli contains opioid synthesizing neurons and has high densities of mu and delta opioid receptors. It is not known which neuronal processes bind opioid receptor ligands. The present experiments will employ experimental localization techniques developed by the P.I. for localizing axonal and dendritic muscarinic acetylcholine receptor subtypes. For whole section analysis one of three types of lesions will be made in rat brain followed by assay of mu and delta-selective ligand binding in cryomicrotome sections, coverslip autoradiography and single grain counting in anterior cingulate cortex: 1) full depth or laminar ibotenic acid, 2) selective destruction of cortical projection neurons following injections of the immunotoxin OX7-ss- saporin into the caudate or periaqueductal gray nuclei or into posterior cingulate cortex, 3) deafferentation undercut lesions. A second localization approach will involve prelabeling of caudate, periaqueductal gray or cortical projection neurons with a stable, retrogradely transported fluorescent dye. Cortical neurons will then be enzymatically and mechanically dissociated and assayed for mu-selective binding of beta-funaltrexamine to prelabeled pyramidal neurons and unlabeled pyramidal and multipolar neurons. Another series of experiments will evaluate mu and delta sites in cortical sublaminae and thalamic subnuclei in cryomicrotome sections of rabbit and human brains. As a number of thalamic and cortical connections are likely involved in sensorimotor aspects of responses to noxious stimuli, multiple label connection studies are also proposed to analyze thalamocortical and corticocortical connections of rabbit cingulate cortex. Studies in thalamus will emphasize the lateral magnocellular nucleus because its connections have not been described and it is not known to exist in any other mammal. Studies at the cortical level will emphasize topographic relations among cingulate areas and among cingulate and visual areas. The main goals of these studies are to elucidate a direct means by which opiate and opioid compounds influence cortical neurons which project to autonomic and somatic motor centers, characterize the distribution of opioid receptors on the dendrites and somata of pyramidal projection neurons and multipolar interneurons and describe the connections of a virtually unknown nucleus in rabbit thalamus. Dissociated adult cortical neurons can be used in future studies to evaluate mechanisms of up and down regulation of opioid receptors as well as gating of ionic channels by opioid compounds.