Schmanke T D, Villablanca J R, Lekht V, Patel H M
Department of Psychiatry and Biobehavioral Sciences, UCLA School of Medicine, CA 90024, USA.
Brain Res Dev Brain Res. 1998 Feb 10;105(2):325-37. doi: 10.1016/s0165-3806(97)00188-0.
Groups of young adult cats with a left hemineodecortication at postnatal (P) ages (in days) 5-15 (P10), 30 (P30) 60 (P60), 90 (P90), 120 (P120) and in adulthood, were used to measure the volume of the thalamus, bilaterally, and of the remaining neocortex (right hemisphere). The same subjects were employed for the behavioral studies reported in the preceding paper. There was a bilateral, age-dependent, thalamic volume decrease. Ipsilateral to the resection, the thalamic shrinkage was the largest for the adult-lesioned cats (by 56.7%) and it was the smallest for the P30 group (43.4%), with a tendency towards a greater atrophy as the age at lesion increased. A similar pattern of atrophy was seen for the contralateral thalamus but the volume reduction was much less pronounced such that it was significant only for the four older age-at-lesion groups (ranging from 18.2% to 11.2% for the P120 and P90 groups respectively). Once again, the shrinkage was the smallest for the P30 group (5.3%). The remaining neocortex also shrunk in these animals, but the volume decrease was significant only for the adult-lesioned (17.8%) and the P120 group (15.4%), while the P30 group had practically no shrinkage (2.4%). The frontal cortex had no atrophy or it was minimal but the shrinkage gradually increased caudally such that all lesioned groups had some size reduction of the occipital cortex. The present results, together with the main conclusion of the preceding paper, indicate that there is a critical maturation period (CMP) of reduced forebrain vulnerability to neocortical injury which, in cats, tends to end between 30 to 60 days postnatally. The implications for developmental brain damage in other higher mammal species as well as the possible morphological ontogenetical underpinnings of this period are discussed.
研究选取了出生后（P）不同年龄阶段的成年幼猫群体，分别为5 - 15日龄（P10）、30日龄（P30）、60日龄（P60）、90日龄（P90）、120日龄（P120）以及成年猫，用于双侧测量丘脑体积以及剩余新皮质（右半球）的体积。同一批实验对象用于前文报道的行为学研究。丘脑体积呈现双侧性、年龄依赖性减小。与切除部位同侧的丘脑，成年期受损猫的萎缩最为严重（减少56.7%），P30组最小（43.4%），且随着损伤时年龄的增加，萎缩有加重趋势。对侧丘脑也呈现类似的萎缩模式，但体积减小不太明显，仅在四个年龄较大的损伤组中显著（P120组和P90组分别为18.2%和11.2%）。同样，P30组的萎缩最小（5.3%）。这些动物的剩余新皮质也出现萎缩，但体积减小仅在成年期受损组（17.8%）和P120组（15.4%）显著，而P30组几乎没有萎缩（2.4%）。额叶皮质无萎缩或萎缩极小，但萎缩程度从前往后逐渐增加，以至于所有损伤组的枕叶皮质都有一定程度的体积减小。本研究结果与前文的主要结论表明，存在一个前脑对新皮质损伤易感性降低的关键成熟期（CMP），在猫中，这个时期倾向于在出生后30至60天之间结束。本文还讨论了这一时期对其他高等哺乳动物物种发育性脑损伤的影响以及可能的形态发生学基础。
