We investigated the effect of brain-derived neurotrophic factor (BDNF) on hippocampal long-term potentiation (LTP) and cognitive functions after global cerebral ischemia in the rat. After four-vessel occlusion, BDNF was administered via an osmotic minipump continuously over 14 days intracerebroventricularly. Electrophysiological experiments were performed 14 days after cerebral ischemia. Test stimuli and tetanization were delivered to the Schaffer collaterals of the hippocampus and field excitatory postsynaptic potentials (fEPSP) were recorded in the CA1 region. Cognitive impairment was analyzed repeatedly with a passive avoidance test, a hole-board test, and with an activity center on the same animal. In sham-operated animals, LTP was consistantly induced after delivering a tetanus (increase of initial slope of fEPSP to 173 +/- 12% of baseline; n = 6). After transient forebrain ischemia LTP could not be induced (117 +/- 4% of baseline; n = 7). In ischemic animals treated with BDNF, LTP could be induced (168 +/- 28% of baseline; n = 8). Transient forebrain ischemia resulted in a significant decrease in spatial discrimination performance but not of associative memory. The ratios for working memory (WM) and reference memory (RM) 15 days after ischemia were lower in the ischemic rats (n = 10) than in the sham-operated control animals (n = 10; WM: 22 +/- 6 vs 72 +/- 7; RM: 30 +/- 7 vs 72 +/- 5). Postischemic intracerebroventricular BDNF infusion increased both WM (63 +/- 4; n = 10) and RM (58 +/- 5; n = 10). The spontaneous locomotor activity did not differ significantly in the three groups. These data indicate a protective effect of BDNF for synaptic transmission and cognitive functions after transient forebrain ischemia.
Download full-text PDF |
Source |
|---|---|
| http://dx.doi.org/10.1006/exnr.1999.7109 | DOI Listing |
Publication Analysis
Top Keywords
Similar Publications
The Impact of Optical Undersampling on the Ca Signal Resolution in Ca Imaging of Spontaneous Neuronal Activity.
J Integr Neurosci
January 2025
Neuroscience Department, University of Connecticut Health, School of Medicine, Institute for Systems Genomics, Farmington, CT 06030, USA.
Background: In neuroscience, Ca imaging is a prevalent technique used to infer neuronal electrical activity, often relying on optical signals recorded at low sampling rates (3 to 30 Hz) across multiple neurons simultaneously. This study investigated whether increasing the sampling rate preserves critical information that may be missed at slower acquisition speeds.
Methods: Primary neuronal cultures were prepared from the cortex of newborn pups.
Resilience of Spontaneously Hypertensive Rats to Secondary Insults After Traumatic Brain Injury: Immediate Seizures, Survival, and Stress Response.
Int J Mol Sci
January 2025
Department of Functional Biochemistry of the Nervous System, Institute of Higher Nervous Activity and Neurophysiology, Russian Academy of Sciences, Moscow 117485, Russia.
Traumatic brain injury (TBI) is one of the primary causes of mortality and disability, with arterial blood pressure being an important factor in the clinical management of TBI. Spontaneously hypertensive rats (SHRs), widely used as a model of essential hypertension and vascular dementia, demonstrate dysfunction of the hypothalamic-pituitary-adrenal axis, which may contribute to glucocorticoid-mediated hippocampal damage. The aim of this study was to assess acute post-TBI seizures, delayed mortality, and hippocampal pathology in SHRs and normotensive Sprague Dawley rats (SDRs).
View Article and Find Full Text PDFTransient cortical beta-frequency oscillations associated with contextual novelty in high density mouse EEG.
Sci Rep
January 2025
Hatherly Laboratories, Department of Clinical and Biomedical Sciences, University of Exeter Medical School, University of Exeter, Prince of Wales Road, Exeter, EX4 4PS, UK.
Beta-frequency oscillations (20-30 Hz) are prominent in both human and rodent electroencephalogram (EEG) recordings. Discrete epochs of beta (or Beta2) oscillations are prevalent in the hippocampus and other brain areas during exploration of novel environments. However, little is known about the spatial distribution and temporal relationships of beta oscillations across the cortex in response to novel contexts.
View Article and Find Full Text PDFPrefrontal cortex synchronization with the hippocampus and parietal cortex is strategy-dependent during spatial learning.
Commun Biol
January 2025
Instituto de Fisiología, Facultad de Ciencias, Universidad de Valparaíso, Valparaíso, Chile.
During spatial learning, subjects progressively adjust their navigation strategies as they acquire experience. The medial prefrontal cortex (mPFC) supports this operation, for which it may integrate information from distributed networks, such as the hippocampus (HPC) and the posterior parietal cortex (PPC). However, the mechanism underlying the prefrontal coordination with HPC and PPC during spatial learning is poorly understood.
View Article and Find Full Text PDFActivation of locus coeruleus noradrenergic neurons rapidly drives homeostatic sleep pressure.
Sci Adv
January 2025
Department of Neuroscience, Helen Wills Neuroscience Institute, Howard Hughes Medical Institute, University of California, Berkeley, Berkeley, CA 94720, USA.
Homeostatic sleep regulation is essential for optimizing the amount and timing of sleep for its revitalizing function, but the mechanism underlying sleep homeostasis remains poorly understood. Here, we show that optogenetic activation of locus coeruleus (LC) noradrenergic neurons immediately increased sleep propensity following a transient wakefulness, contrasting with many other arousal-promoting neurons whose activation induces sustained wakefulness. Fiber photometry showed that repeated optogenetic or sensory stimulation caused a rapid reduction of calcium activity in LC neurons and steep declines in noradrenaline/norepinephrine (NE) release in both the LC and medial prefrontal cortex (mPFC).
View Article and Find Full Text PDFWant AI Summaries of new PubMed Abstracts delivered to your In-box?
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!