Hebbian synaptic learning requires co-activation of presynaptic and postsynaptic neurons. However, under some conditions, information regarding the postsynaptic action potential, carried by backpropagating action potentials, can be strongly degraded before it reaches the distal exhibit Hebbian long-term potentiation (LTP)? Recent results show that LTP can indeed occur at synapses on distal dendrites of hippocamal CA1 neurons, even in the absence of a postsynaptic somatic spike. Instead. local dendritic spikes contribute to the depolarization required to induce LTP. Here, a dendritically constrained synaptic learning rule is proposed, which suggests that nearby synapses can encode temporally contiguous events.
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http://dx.doi.org/10.1016/j.tins.2003.12.004 | DOI Listing |
Animal Model Exp Med
January 2025
Department of Neurology, Tianjin Neurological Institute, Tianjin Medical University General Hospital, Tianjin, China.
Background: Subcortical ischemic vascular dementia (SIVD) is a common subtype of vascular dementia. Currently, the bilateral common carotid artery stenosis (BCAS) mouse model is the most suitable SIVD rodent model. In this study, we investigated the functional and structural impairments in the hippocampus 1 month after BCAS.
View Article and Find Full Text PDFNeurogenetics
January 2025
Department of Surgery, Surgical Research Section, Hamad Medical Corporation, Doha, Qatar.
Memory is a dynamic process of encoding, storing, and retrieving information. It includes sensory, short-term, and long-term memory, each with unique characteristics. Nitric oxide (NO) is a biological messenger synthesized on demand by neuronal nitric oxide synthase (nNOS) through a biochemical process initiated by glutamate binding to NMDA receptors, causing membrane depolarization and calcium influx.
View Article and Find Full Text PDFCells
January 2025
Research Center of Neurology, 125367 Moscow, Russia.
Brain plasticity is at the basis of many cognitive functions, including learning and memory. It includes several mechanisms of synaptic and extrasynaptic changes, neurogenesis, and the formation and elimination of synapses. The plasticity of synaptic transmission involves the expression of immediate early genes (IEGs) that regulate neuronal activity, thereby supporting learning and memory.
View Article and Find Full Text PDFCells
January 2025
Department of Physiology, College of Medicine, Hallym University, Chuncheon 24252, Republic of Korea.
Phosphodiesterase (PDE) enzymes regulate intracellular signaling pathways crucial for brain development and the pathophysiology of neurological disorders. Among the 11 PDE subtypes, PDE4 and PDE5 are particularly significant due to their regulation of cyclic adenosine monophosphate (cAMP) and cyclic guanosine monophosphate (cGMP) signaling, respectively, which are vital for learning, memory, and neuroprotection. This review synthesizes current evidence on the roles of PDE4 and PDE5 in neurological health and disease, focusing on their regulation of second messenger pathways and their implications for brain function.
View Article and Find Full Text PDFAm J Neurodegener Dis
December 2024
Department of Radiology, Carver College of Medicine, University of Iowa Iowa, IA 52242, USA.
Objectives: This study aims to explore the capabilities of dendritic learning within feedforward tree networks (FFTN) in comparison to traditional synaptic plasticity models, particularly in the context of digit recognition tasks using the MNIST dataset.
Methods: We employed FFTNs with nonlinear dendritic segment amplification and Hebbian learning rules to enhance computational efficiency. The MNIST dataset, consisting of 70,000 images of handwritten digits, was used for training and testing.
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