Electrical currents flowing through a dendrite decay in amplitude and change in kinetic properties over distance, with distal synapses experiencing more significant amplitude and kinetic filtering compared to proximal synapses
Neuron morphology influences the amplitude and shape of local EPSPs, but these passive properties alone are insufficient to fully counteract the dendritic filtering effects
Voltage-gated ion channels like Na+ and Ca2+ make dendrites electrically excitable, amplifying EPSPs and potentially triggering dendritic action potentials
Hyperpolarization-activated and A-type K+ channels modulate the duration and spatial characteristics of EPSPs, reducing the location-dependent effects and supporting uniform synaptic integration
Presynaptic properties like the quantum of synaptic vesicles, the number of vesicles released per site, and the number of release sites per terminal
Postsynaptic properties like the density and affinity of receptors, with more receptors potentially placed at distal synapses to compensate for dendritic filtering
Reducing location dependence simplifies the process of achieving synchronous firing across various input patterns, enhancing the neuron's ability to process complex information efficiently
An inhibitory neuron acting directly on a postsynaptic neuron, typically via GABA receptors, leading to the generation of IPSPs and hyperpolarization. The location of the IPSP (axosomatic or near the axon hillock) significantly affects its effectiveness; closer to the axon hillock generally results in greater inhibition of action potential firing
Inhibition mediated by metabotropic receptors (e.g., GABA_B, mGluR) that influence neurotransmitter release, typically occurring at presynaptic sites where neurotransmitters like GABA and glutamate modulate subsequent neurotransmitter release through feedback mechanisms
Inhibition of neurotransmitter release is generally facilitated through the interaction of activated Gβγ subunits with Ca^2+ channels and the SNARE complex, reducing synaptic transmission
Neurons can connect with up to 10,000 presynaptic and postsynaptic neurons, consisting of principal neurons (usually excitatory) and interneurons (usually inhibitory)
Interneurons, depending on their types (e.g., basket cells, Martinotti cells, chandelier cells), target different parts of principal neurons to modulate their activity
A neuron excites a downstream neuron, which in turn excites an inhibitory neuron that loops back to inhibit the original neuron, regulating activity within the circuit
The integration of synaptic excitation and inhibition, facilitated through diverse neuronal network interactions, plays a critical role in processing complex neural information
Synaptic inhibition, whether direct or indirect, significantly shapes the neuronal response and is integral to maintaining the balance and proper function of neural circuits