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Physical exercise has been associated with improved cognition and may even reduce memory deficits after brain injuries. The aims of this work were to: 1) assess whether voluntary physical exercise can reduce the deficits associated with traumatic brain injury (TBI) in two different components of episodic-like memory based on object recognition, temporal order memory ("when"), and object location memory ("where"); and 2) determine whether changes in levels of brain-derived neurotrophic factor (BDNF) in the hippocampus and prefrontal cortex, as well as alterations in hippocampal cytokines, insulin-like growth factor-1 (IGF-1) and vascular endothelial growth factor (VEGF), may influence the effects exercise has on either or both tasks. The rats were distributed into a sham group, a TBI group that remained sedentary (TBI-sed), and a TBI group that had access to a running wheel for a 25-day period from post-injury day 11 (TBI-exe). The rats were sacrificed after the "where" memory task, at post-injury day 37. Physical exercise restored the "when" and "where" memories, which had been impaired by the TBI, and increased the concentration of BDNF in the hippocampus, but not the prefrontal cortex. Neither TBI nor exercise were found to significantly affect hippocampal cytokines, IGF-1 or VEGF at this time post-injury. BDNF levels showed significant positive correlations with exercise, and with "when" (but not "where") memory. These results indicate that post-injury physical exercise restores "when" and "where" object recognition memory tasks after TBI, and that increased BDNF seems to be involved in this effect, particularly with regard to "when" memory., (Copyright © 2020 Elsevier B.V. All rights reserved.)

A number of experiments have shown that physical exercise improves acquisition and retention for a variety of learning tasks in rodents. Most of these works have been conducted with tasks associated with a considerable level of stress, physical effort and/or food deprivation that might interact with exercise, thus hindering the interpretation of the results. On the other hand, it is well established that post-training epinephrine is able to facilitate memory consolidation, but only a few works have studied its effect on the process of acquisition. The present work was aimed at studying whether 17 days of voluntary physical exercise (running wheels) and/or post-training epinephrine (0.01 or 0.05 mg/kg) could improve the acquisition of a spatial task in the Barnes maze, and whether the combination of the two treatments have additive effects. Our results showed that exercise improved acquisition, and 0.01 mg/kg of epinephrine tended to enhance it, by reducing the distance needed to find the escape hole. The combination of both treatments failed to further improve the acquisition level. We concluded that both treatments exerted their effect on acquisition by enhancing the process of learning itself, and that exercise is able to improve acquisition even using tasks with a low level of stress and physical effort., (Copyright © 2013 Elsevier B.V. All rights reserved.)

The present work examined whether post-training systemic epinephrine (EPI) is able to modulate short-term (3h) and long-term (24 h and 48 h) memory of standard object recognition, as well as long-term (24 h) memory of separate "what" (object identity) and "where" (object location) components of object recognition. Although object recognition training is associated to low arousal levels, all the animals received habituation to the training box in order to further reduce emotional arousal. Post-training EPI improved long-term (24 h and 48 h), but not short-term (3 h), memory in the standard object recognition task, as well as 24 h memory for both object identity and object location. These data indicate that post-training epinephrine: (1) facilitates long-term memory for standard object recognition; (2) exerts separate facilitatory effects on "what" (object identity) and "where" (object location) components of object recognition; and (3) is capable of improving memory for a low arousing task even in highly habituated rats.

The effect of long-term voluntary exercise (running wheel) on anxiety-like behaviour (plus maze and open field) and learning and memory processes (object recognition and two-way active avoidance) was examined on Wistar rats. Because major individual differences in running wheel behaviour were observed, the data were analysed considering the exercising animals both as a whole and grouped according to the time spent in the running wheel (low, high, and very-high running). Although some variables related to anxiety-like behaviour seem to reflect an anxiogenic compatible effect, the view of the complete set of variables could be interpreted as an enhancement of defensive and risk assessment behaviours in exercised animals, without major differences depending on the exercise level. Effects on learning and memory processes were dependent on task and level of exercise. Two-way avoidance was not affected either in the acquisition or in the retention session, while the retention of object recognition task was affected. In this latter task, an enhancement in low running subjects and impairment in high and very-high running animals were observed.

A new method of automated sleep-wake staging in the rat is described. Hippocampal electroencephalographic (HPC) and nuchal electromyographic signals were recorded by a digital polygraph. The HPC channel was filtered off-line to obtain the original plus theta and delta waves. Statistics of each of these four channels were obtained every 5 s and exported to a standard spreadsheet. The automated staging consisted of five steps: (1) automatic detection of waking, nonrapid eye movement sleep and rapid eye movement sleep patterns (5-s periods); (2) calculation of statistics for each vigilance state; (3) final classification of 5-s periods; (4) construction of a primary 20-s epoch hypnogram; and (5) automatic refinement of the previous hypnogram. The system includes indices about the accuracy of the staging and was validated with five recordings of 23 h each. The global agreement between human and automatic scoring in the validation recordings was 94.32%.

Septal lesions impair a variety of tasks, including inhibitory avoidance and one way active avoidance. In contrast, these lesions improve two-way active avoidance, probably by reducing anxiety. The present work aimed to study whether anterodorsal medial septal lesion (a) improves performance of two-way active avoidance task (Experiment I), as it has been observed with wider septal lesion, and (b) affect anxiety and/or locomotor activity (Experiment II). This precise region was chosen because some evidences suggest that its lesion do not lead to a reduction of anxiety. Lesioned rats tended to make a higher, but statistically non-significant (P=0.074), number of avoidances regardless of the session, being this difference statistically significant on the retention session (RT). The same lesion did not appear to have an anxiolytic effect, and did not affected basal locomotor activity. Different possible explanations of our results are discussed.