Environmental enrichment reduces brain excitability in adult rats overnourished during lactation

ABSTRACT Objective: This study aimed to analyze whether exposure to environmental enrichment (EE) during the juvenile phase of life interferes with the electrical activity of the adult rat brain. In addition, the present research also investigated whether this putative effect on brain electrical activity could be affected by prior overnutrition during lactation. Electrophysiology was measured through cortical spreading depression (CSD), a phenomenon related to brain excitability. Methods: Wistar rats were suckled in litters of either nine or three pups, forming the nourished (N) or overnourished (ON) groups, respectively. At 36 days old, half of the animals from each nutritional condition were exposed to EE. The other half was kept in the standard environment (SE). At 90-120 days of life, each animal was anesthetized for CSD recordings. Results: Overnutrition during lactation caused increases (p < 0.05) in body and brain weights. The EE decelerated CSD propagation velocity regardless of nutritional state during lactation (p < 0.001). The CSD deceleration in the N-EE group was 23.8% and in the ON-EE group was 15% in comparison with the N-SE and ON-SE groups, respectively. Conclusion: Our data demonstrated that EE exposure in the juvenile phase of the rat's life reduced brain excitability, and this effect was observed even if animals were overnourished during lactation. An EE could be considered an adjuvant therapeutic resource to modulate brain excitability.

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Competition of glycerol with other oxidizable substrates in rat brain

Biochemical Journal ◽

10.1042/bj2370047 ◽

1986 ◽

Vol 237 (1) ◽

pp. 47-51 ◽

Cited By ~ 11

Author(s):

M C McKenna ◽

L I Bezold ◽

S J Kimatian ◽

J T Tildon

Keyword(s):

Rat Brain ◽

Glutamine Metabolism ◽

Glycerol Oxidation ◽

Adult Rats ◽

Adult Rat ◽

Rat Pups ◽

Age Related ◽

Adult Rat Brain ◽

14Co2 Production ◽

Age Related Changes

The rate of conversion of [1,3-14C]glycerol into 14CO2 was measured in the presence and absence of unlabelled alternative substrates in whole homogenates from the brains of young (4-6 and 18-20 days old) and adult rats. Unlabelled glucose decreased 14CO2 production from [1,3-14C]glycerol by about 40% at all ages studied. Unlabelled 3-hydroxybutyrate significantly decreased the 14CO2 production from both low (0.2 mM) and high (2.0 mM) concentrations of glycerol in 4-6- and 18-20-day-old rat pups. However, the addition of 3-hydroxybutyrate had no effect on the rate of 14CO2 production from 2.0 mM-glycerol in adult rats, suggesting that the interaction of 3-hydroxybutyrate with glycerol in adult rat brain is complex and may be related to the biphasic kinetics previously reported for glycerol oxidation. Unlabelled glutamine decreased the production of 14CO2 by brain homogenates from 18-20-day-old and adult rats, but not in 4-6-day-old rat pups. In the converse situation, the addition of unlabelled glycerol to whole brain homogenates had little effect on the rate of 14CO2 production from [6-14C]glucose, 3-hydroxy[3-14C]butyrate and [U-14C]glutamine, although some significant differences were noted. Collectively these results suggest that glycerol and these other substrates may be metabolized in separate subcellular compartments in brain such that the products of glucose, 3-hydroxybutyrate and glutamine metabolism can dilute the oxidation of glycerol, but the converse cannot occur. The data also demonstrate that there are complex age-related changes in the interaction of glycerol with 3-hydroxybutyrate and glutamine. The fact that glycerol oxidation was only partially suppressed by the addition of 1-5 mM-glucose, -3-hydroxybutyrate or -glutamine could also suggest that glycerol may be selectively utilized as an energy substrate in some discrete brain region.

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Pattern of chondroitin sulfate proteoglycan expression after ablation of the sensorimotor cortex of the neonatal and adult rat brain

Archives of Biological Sciences ◽

10.2298/abs0804581d ◽

2008 ◽

Vol 60 (4) ◽

pp. 581-591

Author(s):

Sanja Dacic ◽

Sanja Pekovic ◽

Maja Stojiljkovic ◽

Irena Lavrnja ◽

Danijela Stojkov ◽

...

Keyword(s):

Chondroitin Sulfate ◽

Rat Brain ◽

Sensorimotor Cortex ◽

Immunohistochemical Analysis ◽

Recovery Process ◽

Adult Brain ◽

Sulfate Proteoglycan ◽

Adult Rats ◽

Adult Rat ◽

Adult Rat Brain

The central nervous system has a limited capacity for self-repair after damage. However, the neonatal brain has agreater capacity for recovery than the adult brain. These differences in the regenerative capability depend on local environmental factors and the maturational stage of growing axons. Among molecules which have both growth-promoting and growth-inhibiting activities is the heterogeneous class of chondroitin sulfate proteoglycans (CSPGs). In this paper, we investigated the chondroitin-4 and chondroitin-6 sulfate proteoglycan expression profile after left sensorimotor cortex ablation of the neonatal and adult rat brain. Immunohistochemical analysis revealed that compared to the normal uninjured cortex, lesion provoked up regulation of CSPGs showing a different pattern of expression in the neonatal vs. the adult brain. Punctuate and membrane-bound labeling was predominate after neonatal lesion, where as heavy deposition of staining in the extracellular matrix was observed after adult lesion. Heavy deposition of CSPG immunoreactivity around the lesionsite in adult rats, in contrast to a less CSPG-rich environment in neonatal rats, indicated that enhancement of the recovery process after neonatal injury is due to amore permissive environment.

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Ketamine alone or combined with midazolam or dexmedetomidine does not affect anxiety-like behaviours and memory in adult Wistar rats

Laboratory Animals ◽

10.1177/0023677216652380 ◽

2016 ◽

Vol 51 (2) ◽

pp. 147-159 ◽

Cited By ~ 6

Author(s):

Ana Magalhães ◽

Ana Valentim ◽

Carlos Venâncio ◽

Mariana Pereira ◽

Pedro Melo ◽

...

Keyword(s):

Recognition Memory ◽

Wistar Rats ◽

Radial Maze ◽

Emotional Reactivity ◽

Scientific Data ◽

Laboratory Animals ◽

Adult Rats ◽

Adult Rat ◽

Plus Maze

Ketamine administration has been associated with controversial behavioural impairments and psychotic episodes. Even though ketamine alone and in combination with midazolam or dexmedetomidine are frequently used in laboratory animals, the side-effects of such protocols are not well known. Therefore, our aim was to evaluate the effects of ketamine alone and in combination with midazolam or dexmedetomidine on emotional reactivity, as well as the effects on learning and memory in adult rats at least 48 h after anaesthesia. The evaluation of the potential influence of 100 mg/kg ketamine administered alone and in combination with midazolam (5 mg/kg), or dexmedetomidine (0.25 mg/kg) on spatial learning and recognition memory was studied in adult Wistar rats using the radial maze as well as object recognition and location tests. The influence of these combinations on emotional reactivity was investigated using the new exploration test and the elevated plus maze. Results showed that ketamine alone or in combination with midazolam or dexmedetomidine affected neither spatial and recognition memory, nor emotional reactivity. These results reinforce the safe clinical use of ketamine and its combinations in rats in a research context since the administration of these anaesthetic combinations did not produce significant changes with regard to spatial and recognition memory or emotional reactivity. Furthermore, these results indicate that the quality of scientific data produced in adult rat neurobehavioural research is not jeopardized by the use of these anaesthetic protocols.

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Subchronic effects of ochratoxin A on young adult rat brain and partial prevention by aspartame, a sweetener

Human & Experimental Toxicology ◽

10.1177/096032719801700704 ◽

1998 ◽

Vol 17 (7) ◽

pp. 380-386 ◽

Cited By ~ 7

Author(s):

A Belmadani ◽

G Tramu ◽

A M Betbeder ◽

E E Creppy

Keyword(s):

Young Adult ◽

Ochratoxin A ◽

Duration Of Treatment ◽

Nuclear Effect ◽

Penicillium Species ◽

Adult Rats ◽

Adult Rat ◽

Adult Rat Brain ◽

The Brain ◽

Amino Acid Concentrations

1. Ochratoxin A (OTA) is a mycotoxin produced by several fungi, especially Aspergillus and Penicillium species. Many food and foodstuffs can be contaminated by ochratoxin A, which is consequently found in blood of animals and humans. 2. The distribution into the brain of young adult rats fed OTA for 1 to 6 weeks and some consequences have been investigated in the present study. 3. Our results on rats given OTA (289 mg/kg/48 h) indicated that OTA accumulated in the whole brain as function of time according to a regression curve, Y=78.723 a+16.72 with a correlation coefficient of r=0.989, where Y-axis is the OTA concentration in ng/ g of brain and X-axis is the duration of the treatment in weeks. The brain OTA contents was 11.95+2.2, 23.89+4.4, 39.9+4.5, 50.3+7.3, 78.8+6.3, 94+16 ng/g of brain in the mycotoxin-treated animals for respectively 1, 2, 3, 4, 5 and 6-weeks treatment. OTA induced modifications of free amino-acid concentrations in the brain, mainly, Tyrosine (Tyr) and phenylalanine (Phe). Tyr decreased significantly as compared to control (p50.05). Phe increased signifi-cantly as compared to control (p<50.05). 4. Aspartame, (25 mg/kg/48 h) a structural analogue of OTA largely modified the distribution and prevented the accumulation of OTA in the brain since the respective brain OTA contents decreased respectively to 9.6+7.9, 19.2+3.0, 26.8+4.2, 19.7+1.9, 13.7+5.6 and 11.0+6.0 ng/g of tissue, for the same duration of treatment. It also prevented the modifications of Tyr and Phe levels. 5. The histological investigations showed several necrotic cells with pyknotic nucleus, detected in OTA treated animals with higher frequency as compared to the controls and Aspartame treated ones. Aspar-tame appeared to significantly prevent this nuclear effect as well, the meaning of which is discussed.

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Favorable and unfavorable lactation modulates the effects of electrical stimulation on brain excitability: A spreading depression study in adult rats

Life Sciences ◽

10.1016/j.lfs.2012.07.011 ◽

2012 ◽

Vol 91 (9-10) ◽

pp. 306-311 ◽

Cited By ~ 4

Author(s):

M. Batista-de-Oliveira ◽

K.K. Monte-Silva-Machado ◽

A.K. Paiva ◽

H. Lima ◽

F. Fregni ◽

...

Keyword(s):

Electrical Stimulation ◽

Spreading Depression ◽

Adult Rats ◽

Brain Excitability

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Environmental enrichment promotes fiber sprouting after deafferentation of the superior colliculus in the adult rat brain

Experimental Neurology ◽

10.1016/j.expneurol.2008.12.016 ◽

2009 ◽

Vol 216 (2) ◽

pp. 515-519 ◽

Cited By ~ 8

Author(s):

Matteo Caleo ◽

Daniela Tropea ◽

Chiara Rossi ◽

Laura Gianfranceschi ◽

Lamberto Maffei

Keyword(s):

Superior Colliculus ◽

Rat Brain ◽

Environmental Enrichment ◽

Adult Rat ◽

Adult Rat Brain

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Continuous environmental enrichment and aerobic exercise improves spatial memory: focus on rat hippocampal BDNF and NGF

Comparative Exercise Physiology ◽

10.3920/cep190036 ◽

2020 ◽

Vol 16 (2) ◽

pp. 121-128

Author(s):

D.I.I. Santoso ◽

S. Yolanda ◽

S. Redjeki ◽

T. Andraini ◽

K. Ivanali

Keyword(s):

Aerobic Exercise ◽

Wistar Rats ◽

Environmental Enrichment ◽

Memory Function ◽

Combination Group ◽

Adult Rats ◽

Positive Effects ◽

Y Maze ◽

Function Test ◽

Male Wistar Rats

Memory is an important cognitive function in humans. Exercise and environmental enrichment (EE) exposure have positive effects on memory function via improved neurogenesis through expression of growth factors such as brain-derived neurotrophic factor (BDNF) and nerve growth factor (NGF). Exercise and environmental enrichment have independently been shown to increase BDNF and NGF, but the effect of the combination of these treatments has not been widely studied. This experimental study aims to analyse the effect of aerobic exercise, EE exposure, and combination of aerobic exercise and EE exposure on memory function. This study used twenty 7-month old male Wistar rats that were given treatment for 8 weeks. Memory function was tested using forced alternation Y-maze. Hippocampal expression of BDNF and NGF were also assessed. The results showed the combination group has highest performance in memory function test and also the highest level of hippocampal BDNF and NGF (P<0.05). It can be concluded that the combination of aerobic exercise and continuous EE exposure produces the best results for memory function through higher levels of hippocampal BDNF and NGF in adult rats.

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