USSR Cardiology Research Center, Academy of Medical Sciences, Moscow.
Int J Neurosci. 1989 Sep;48(1-2):105-24. doi: 10.3109/00207458909002155.
Directional behavioral and functional asymmetries (i.e., left-biased or right-biased in all or most animals of the population) induced by certain chemical substances are new types of brain and spinal cord asymmetry. The revealed asymmetry comprises: (1) left- or right-biased circle rotation in rat, (2) hind limb postural asymmetry resulting from alteration of the left or right flexion reflex in rat and cat, and (3) asymmetric alterations of the evoked potentials (EP) in the turtle visual cortex. Circle rotation of animals is induced by hypothalamic neurohormones (somatostatin, LH-RH, substance P, and TRH). Postural asymmetry develops under the effect produced by enkephalins and opioid kappa- and delta-agonists, sigma-agonist SKF 10.047, Arg-vasopressin. Endogenous peptide factors, the activity (or content) of which increased under brain and spinal cord unilateral injury, as well as the ones localized in the left or right hemisphere, also induced postural asymmetry. EP of the left and right turtle visual cortex were inhibited by enkephalins and opioid kappa-, and delta- and mu-agonists, and factors predominantly localized in the left or right turtle visual cortex in a different manner. The data reported here suggest the existence of a side-specific mechanism for a selective neurohormonal regulation of the neuronal activity and other processes in the left and right halves of brain and spinal cord which involves lateralized neuropeptides and their receptors. This mechanism might serve to maintain a certain balance between the activity of the left and right-side neurons, and other contralateral processes in the paired and bilateral structures in brain and spinal cord. Significant deviations from the balance occur most likely due to powerful unilateral stimuli, e.g., unilateral trauma. Many neuropeptides (opioid ones, somatostatin, MSH, ACTH) are, presumably, involved in the regeneration processes in the central and peripheral nervous system. In the case of brain lesions, some lateralized endogenous peptides may participate in the regulation of regeneration process on the left, whereas the other ones, on the right side of the midline, which depends on the side of the lesion. Some lateralized receptors and ligands may serve as positional markers of the left, whereas the other ones may serve as those of the right brain hemisphere. In ontogenesis, these markers are probably necessary to perform the function of the mechanism responsible for symmetrical brain formation.
某些化学物质诱导产生的定向行为和功能不对称（即群体中所有或大多数动物表现出左偏或右偏）是脑和脊髓不对称的新型类型。所揭示的不对称包括：（1）大鼠的左偏或右偏转圈行为，（2）大鼠和猫因左或右屈肌反射改变而导致的后肢姿势不对称，以及（3）乌龟视觉皮层诱发电位（EP）的不对称改变。动物的转圈行为由下丘脑神经激素（生长抑素、促黄体激素释放激素、P物质和促甲状腺激素释放激素）诱导。姿势不对称是在脑啡肽、阿片κ和δ激动剂、σ激动剂SKF 10.047、精氨酸加压素的作用下产生的。内源性肽因子在脑和脊髓单侧损伤后其活性（或含量）增加，以及那些定位于左或右半球的肽因子，也会诱导姿势不对称。乌龟左右视觉皮层的EP受到脑啡肽、阿片κ、δ和μ激动剂以及主要定位于乌龟左右视觉皮层的因子的不同方式抑制。此处报道的数据表明存在一种侧特异性机制，用于对脑和脊髓左右半侧的神经元活动及其他过程进行选择性神经激素调节，这涉及到侧化的神经肽及其受体。该机制可能有助于维持左右侧神经元活动以及脑和脊髓中配对和双侧结构中其他对侧过程之间的某种平衡。很可能由于强大的单侧刺激，如单侧创伤，导致平衡出现显著偏差。许多神经肽（阿片类、生长抑素、促黑素、促肾上腺皮质激素）大概参与中枢和外周神经系统的再生过程。在脑损伤的情况下，一些侧化的内源性肽可能参与左侧再生过程的调节，而另一些则参与中线右侧的再生过程，这取决于损伤的一侧。一些侧化的受体和配体可能作为左脑的位置标记，而另一些可能作为右脑半球的位置标记。在个体发育过程中，这些标记可能对于执行负责对称脑形成的机制的功能是必要的。
