Preserved spatial memory in old rats survives 10 months without training

Aged rats with extensive prior training on the radial maze retain the capacity for accurate spatial working memory (WM) for at least 3 months without practice. To investigate the temporal limits of this influence of prior experience we compared the reacquisition of spatial WM by a group of experienced 21.5-month-old rats to the original acquisition by naive 3-month-old rats. The aged rats had received 225 radial maze tests between 3 and 11 months of age. Despite 10 months without practice the old rats rapidly reacquired critical performance. Their reacquisition was markedly superior to original learning by the young rats, even when delays as long as 5 h were imposed between the rats' fourth and fifth choices during the daily tests in the eight-arm maze. Additional tests showed that neither young nor old rats employed a response strategy to maintain accurate spatial WM performance. Experience clearly confers long-lived protection against the otherwise deleterious effects of aging on spatial WM, but the mechanism by which this influence arises is unknown.     

Cue depreciation: when word fragment completion is undermined by prior exposure to lesser fragments

The ability to think of a previously studied item has often been shown to be impaired when, in one way or another, the extraitem context is changed from study to test. In a series of five experiments, such impairment is induced in a somewhat different way. A fragment (e.g. r-i--rop) of a just-studied word (raindrop) is shown to be less readily completed if it is presented bit by bit (r------p, r----r-p, r-i--r-p, r-i--rop) rather than all at once (Experiments 1, 3, 4, and 5). No such effect is found if the word has not been studied beforehand (Experiments 2, 3, 4, and 5). This pattern of results occurs even when fragments of studied and nonstudied words occur in the same test and under conditions in which subjects cannot tell whether a given fragment is of a studied or nonstudied word (Experiments 4 and 5). In addition, for words that have been studied beforehand, the impairment is shown to increase systematically with the number of steps involved in the presentation of the word fragment (Experiment 3) and also to persist when the time allowed for completion of the final version of the fragment is increased from 4 s to a full minute (Experiment 5).     

社会应激对成年后进行群体隔离的大白鼠的行为的影响

本文观察了在成年后进行群体隔离的大白鼠与群居鼠在摄食、饮水、睡眠等方面的行为差异。着重观察了社会应激对成年后进行群体隔离的动物的行为的影响,以研究群体隔离时动物的年龄与过去生活经验是不是动物在社会应激时发生的行为改变的关键因素。 结果表明:群居与隔离两种环境对动物摄食、饮水和体重无明显影响,但隔离动物睡眠时间较群居动物短。即使在成年后进行群体隔离、社会应激对隔离动物的摄食、饮水、睡眠和攻击性行为的影响也比群居组明显。但进行群体隔离时动物的年龄和隔离前有较长时间的群居生活经验可大大减轻社会应激时行为反应的强度,也可使适应过程发生得快些。这说明早期环境和过去生活经验的重要性。社会应激影响饮水和摄食的方式随年龄而改变,年龄较大的群居鼠对社会应激的适应可能比年龄较轻的群居鼠差。     

Catamnestic surveys on somato-psychosocial development in childhood and adolescence of patients with unipolar depressive and bipolar manic-depressive psychoses

The somatic and psychosocial development of 80 subjects with manifest affective-phasic psychoses is studied retrospectively and compared with that of an identically sized control group consisting of neuropsychiatrically healthy subjects. Statistically significant differences were found particularly in the answers to questions dealing with social situation and social adaptability. Achievement at school and vocational qualifications were lower among the parents of the patients than among those of the healthy subjects. Characteristic features of the patients' childhood and adolescence were transient depression, often for no apparent cause, and maladaption, and vocational wishes were fulfilled less often than among the controls. The patients experienced greater difficulty in settling in to a new group due to their contact difficulties.     

Acoustically evoked brain stem potential in Wilson disease

By 48 patients with Wilson's disease the brainstem acoustic evoked potentials were stated. There were 35 pathological findings (73%), 13 were normal (27%). The waves, determined by the middle and upper brainstem (Pons and Mesencephalon) showed most of all pathological changes. Those patients with forms of Wilson's disease called Pseudoskelerose and Pseudoparkinson showed the most pathological findings. But one could watch these findings by about 30% of patients in preclinical stage. This method can possibly be used for early detection of disorders of brainstem functions and in the same way it can be used for control of treatment by patients in preclinical stage.