8 arm radial maze

BACKGROUND: In children, hearing loss has been associated with hyperactivity, disturbed social interaction, and risk of cognitive disturbances. Mechanistic explanations of these relations sometimes involve language. To investigate the effect of hearing loss on behavioral deficits in the absence of language, we tested the impact of hearing loss in juvenile rats on motor, social, and cognitive behavior and on physiology of prefrontal cortex. METHODS: Hearing loss was induced in juvenile (postnatal day 14) male Sprague-Dawley rats by intracochlear injection of neomycin under general anesthesia...

Novelty detection, crucial to episodic memory formation, is impaired in epileptic patients with mesial temporal lobe resection. Mismatch novelty detection, that activates the hippocampal CA1 area in humans and is vital for memory reformulation and reconsolidation, is also impaired in patients with hippocampal lesions. In this work, we investigated the response to mismatch novelty, as occurs with the new location of known objects in a familiar environment, in the Li2+ -pilocarpine rat model of TLE and its correlation with hippocampal monoaminergic markers...

Animal models of traumatic brain injury (TBI) have shown that impaired motor and cognitive function can be improved by physical exercise. However, not each animal with TBI can be well rehabilitated at the same training intensity due to a high inter-subject variability. Hence, this paper presents a two-stage wheel-based mixed-mode rehabilitation mechanism by which the effect of stress on the rehabilitation performance was investigated. The mixed-mode rehabilitation mechanism consists of a two-week adaptive and a one-week voluntary rehabilitation program as Stages 1 and 2, respectively...

Methamphetamine (MA) is a highly addictive drug, and MA use disorder is often comorbid with anxiety and cognitive impairment. These comorbid conditions are theorized to reflect glutamate-related neurotoxicity within the frontal cortical regions. However, our prior studies of MA-sensitized mice indicate that subchronic, behaviorally non-contingent MA treatment is sufficient to dysregulate glutamate transmission in mouse brain. Here, we extend this prior work to a mouse model of high-dose oral MA self-administration (0...

Spatial memory encoding depends in part on cholinergic modulation. How acetylcholine supports spatial memory encoding is not well understood. Prior studies indicate that acetylcholine release is correlated with exploration, including epochs of rearing onto hind legs. Here, to test whether elevated cholinergic tone increases the probability of rearing, we tracked rearing frequency and duration while optogenetically modulating the activity of choline acetyltransferase containing (i.e., acetylcholine producing) neurons of the medial septum in rats performing a spatial working memory task (n = 17 rats)...

BACKGROUND: Bain ischemia is a disease that occurs for various reasons, induces reactive oxygen species (ROS), and causes fatal damage to the nervous system. Protective effect of HPCA on ischemic injury has not been extensively studied despite its significance in regulating calcium homeostasis and promoting neuronal survival in CA1 region of the brain. OBJECTIVE: We investigate the role of HPCA in ischemic injury using a cell-permeable Tat peptide fused HPCA protein (Tat-HPCA)...

Melissa officinalis and Panax ginseng extracts were investigated to determine combinatorial effects on cognitive behaviors' of albino-rats. The study was prospective-experimental; lasted from June-2022 to March-2023. Learning and memory measurements were done by animal-models. Data analyzed by 22nd version of SPSS. In Passive-avoidance-test both doses of Melissa officinalis and Panax ginseng (100/100mg/kg and 200/200mg/kg) showed significant differences in number of acquisition-trial between groups (p<0...

Spatial memory encoding depends in part on cholinergic modulation. How acetylcholine supports spatial memory encoding is not well understood. Studies of rearing onto hind legs, a representative exploratory behavior, suggest that acetylcholine release promotes rearing. Here, to test this hypothesis, we tracked rearing while optogenetically modulating the activity of choline acetyltransferase containing (i.e., acetylcholine producing) neurons of the medial septum in rats performing a spatial working memory task (n=9 rats)...

Stimulant-use disorders can present with long-term cognitive and mental health deficits. Little is known about the underlying molecular mechanisms perpetuating sex differences in cognitive and behavioral deficits in preclinical models of addiction to stimulants such as methamphetamine (MA). The current study investigated the neurochemical shifts underlying sex disparities in MA-induced working memory deficits and an addictive phenotype following abstinence from chronic MA abuse. We used our previously reported mouse model of voluntary oral methamphetamine administration (VOMA) consisting of an acquisition phase (days 1-14) characterized by escalating doses of MA and a binge phase (days 14-28) characterized by static doses...

Previous studies have highlighted an important role for hippocampal sharp-wave ripples in spatial alternation learning, as well as in modulating activity in the medial prefrontal cortex (mPFC). However, the direct influence of hippocampal sharp-wave ripples on mPFC activity during spatial alternation learning has not been investigated. Here, we train Long Evans rats on a three-arm radial maze to perform a sequence of alternations. Three alternation sequences needed to be learned, and while learning a sequence, the activity in the mPFC was inhibited either directly following sharp-wave ripples in the hippocampus (on-time condition) or with a randomized delay (delayed condition)...

Adult neurogenesis in the dentate gyrus plays an important role for pattern separation, the process of separating similar inputs and forming distinct neural representations. Estradiol modulates neurogenesis and hippocampus function, but to date no examination of estradiol's effects on pattern separation have been conducted. Here, we examined estrogenic regulation of adult neurogenesis and functional connectivity in the hippocampus after the spatial pattern separation task in female rats. Ovariectomized Sprague-Dawley rats received daily injections of vehicle, 0...

Obstructive sleep apnea-hypopnea syndrome (OSAHS) is involved in cognitive impairment of children. Chronic intermittent hypoxia (CIH) is considered as the critical pathophysiological mechanism of OSAHS. Calcium sensitive receptor (CaSR) mediated apoptosis in many neurological disease models by endoplasmic reticulum stress (ERS)-related pathway. However, little is known about the role of CaSR in OSAHS-induced cognitive dysfunction. In this study, we explored the effect of CaSR on CIH-induced cognitive impairment and possible mechanisms on regulation of PERK-ATF4-CHOP pathway in vivo and in vitro...

The mitochondrial calcium uniporter (MCU) is the main route of calcium (Ca2+ ) entry into neuronal mitochondria. This channel has been linked to mitochondrial Ca2+ overload and cell death under neurotoxic conditions, but its physiologic roles for normal brain function remain poorly understood. Despite high expression of MCU in excitatory hippocampal neurons, it is unknown whether this channel is required for learning and memory. Here, we genetically down-regulated the Mcu gene in dentate granule cells (DGCs) of the hippocampus and found that this manipulation increases the overall respiratory activity of mitochondrial complexes I and II, augmenting the generation of reactive oxygen species in the context of impaired electron transport chain...

The nucleus accumbens (NAc) is considered an interface between motivation and action, with NAc neurons playing an important role in promoting reward approach. However, the encoding by NAc neurons that contributes to this role remains unknown. We recorded 62 NAc neurons in male Wistar rats (n = 5) running towards rewarded locations in an 8-arm radial maze. Variables related to locomotor approach kinematics were the best predictors of the firing rate for most NAc neurons. Nearly 18% of the recorded neurons were inhibited during the entire approach run (locomotion-off cells), suggesting that reduction in firing of these neurons promotes initiation of locomotor approach...

CD36, a fatty acid translocator and NRF2, a transcription factor, are two important players in inflammation and oxidative stress, including in the central nervous system. Both were associated with neurodegeneration as tilting arms of a balance: while activation of CD36 participates in neuroinflammation, activation of NRF2 seems to protect against oxidative stress and neuroinflammation. This study aimed to establish whether tilting the balance one way or the other, by knocking out either of them (NRF2-/- or CD36-/-), would show that one holds higher weight over the other in the cognitive behaviour of mice...

Alzheimer's disease (AD) is a chronic and progressive neurodegenerative disorder characterized by abnormal accumulation of extracellular β-amyloid (Aβ) plaques and neuronal damage. Although AD is typically considered a cognitive neurodegenerative disorder, almost all people diagnosed with AD develop neuropsychiatric complications at some stage in their life span. The present study investigated the effect of chronic Nattokinase (NK) administration on β-Amyloid peptide (Aβ1-42 ) induced neuropsychiatric conditions (depression-like behaviour, anxiety, and memory impairment) in mice...

Chronic cerebral hypoperfusion is an important pathological factor in many neurodegenerative diseases, such as cerebral small vessel disease (CSVD). One of the most used animal models for chronic cerebral hypoperfusion is the bilateral common carotid artery stenosis (BCAS) mouse. For the therapy of CSVD and other diseases, it will be beneficial to understand the pathological alterations of the BCAS mouse, particularly vascular pathological changes. A mouse model of BCAS was used, and 8 weeks later, cognitive function of the mice was examined by using novel object recognition test and eight-arm radial maze test...

The deep layers of medial entorhinal cortex (MEC) are considered a crucial station for spatial cognition and memory. The deep sublayer Va of MEC (MECVa) serves as the output stage of the entorhinal-hippocampal system and sends extensive projections to brain cortical areas. However, the functional heterogeneity of these efferent neurons in MECVa is poorly understood, due to the difficulty of performing single-neuron activity recording from the narrow band of cell population while the animals are behaving. In the current study, we combined multi-electrode electrophysiological recording and optical stimulation to record cortical-projecting MECVa neurons at single-neuron resolution in freely moving mice...

Propranolol is the treatment of choice for infantile hemangioma. We investigated the effects of long-term propranolol use in early infancy on learning and memory later in life in mice. At three weeks of age, mice were randomly divided into six experimental groups. Groups 1 and 2 (controls) received only saline for 21 days. Groups 3 and 4 received propranolol (2.5 mg/kg) for 21 days. Groups 5 and 6 received propranolol (5 mg/kg) for 21 days. Groups 1, 3 and 5 were tested at the end of 21 days of treatment (week 6)...

BACKGROUND: Bioaccumulation of aluminum in the brain is associated with adverse neuroinflammatory and neurodegenerative changes, such as those seen in Alzheimer's disease (AD). OBJECTIVE: This study aimed to assess the impact of the administration of Lepidium sativum (LS) extract on behavioral, biochemical, and cerebral histopathological changes in rats with AlCl3 -induced AD and explore the mechanism behind this effect. MATERIALS AND METHODS: This study was conducted on 40 male albino rats divided into four groups (n=10): LS (control, 20 mg/kg body weight for 8 weeks), AD (AlCl3, 10 mg/kg body weight), and an LS-treated AD group...