Lec 21/22 SAQ - Neurons and Glia

Neurons are responsible for transmitting and processing information in the nervous system.

The main components of a neuron are the cell body, dendrites, and axon.

Ions play a crucial role in the generation and transmission of electrical signals in neurons.

<p>Ions can move across the cell membrane through diffusion through ion channels or active transport/facilitated diffusion.</p> Signup and view all the answers

<p>The membrane potential refers to the voltage difference across a cell membrane.</p> Signup and view all the answers

<p>The resting membrane potential is the voltage difference across a cell membrane when the neuron is at rest.</p> Signup and view all the answers

<p>The unequal distribution of ions (Na+, K+, Cl-) across the cell membrane is the main factor contributing to the resting membrane potential.</p> Signup and view all the answers

<p>The Na+/K+ electrogenic pump maintains the concentration gradient of sodium and potassium ions across the cell membrane.</p> Signup and view all the answers

<p>The resting membrane potential generally ranges between -60 to -80 mV.</p> Signup and view all the answers

<p>The concentration gradient and the electrical gradient are the two gradients that influence ion movement.</p> Signup and view all the answers

<p>EK+=RT loge [K+]o zF [K+]i</p> Signup and view all the answers

<p>Resting membrane potential is generally between -60 to -80 mV</p> Signup and view all the answers

<p>It pumps out 3 Na+ ions and pumps in 2 K+ ions, creating a negative inside relative to the outside</p> Signup and view all the answers

<p>Voltage-gated and ligand-gated ion channels</p> Signup and view all the answers

<p>The threshold is a voltage of approximately +15mV</p> Signup and view all the answers

<p>The activation gate opens, allowing Na+ influx, and the inactivation gate closes, creating a refractory period</p> Signup and view all the answers

<p>The opening of voltage-gated K+ channels</p> Signup and view all the answers

<p>It is the propagation of action potentials in myelinated axons, jumping from one node of Ranvier to another</p> Signup and view all the answers

<p>Schwann cells in the peripheral nervous system (PNS) and oligodendrocytes in the central nervous system (CNS)</p> Signup and view all the answers

<p>Astrocytes provide structural support, control the extracellular environment around neurons, and release growth factors to nourish and protect neurons</p> Signup and view all the answers

<p>Astrocytes trigger synapse formation in the central nervous system and are necessary for synapse maintenance.</p> Signup and view all the answers

<p>Macroglia, including astrocytes, regulate synapse number, stability, and function.</p> Signup and view all the answers

<p>Yes, adult hippocampal stem cells display dependence on astrocytes for synapse formation.</p> Signup and view all the answers

<p>Yes, there is evidence that schwann cells in the periphery can trigger neuromuscular junction formation.</p> Signup and view all the answers

<p>Glia in culture can sense synaptic activity and respond by generating calcium transient currents and releasing gliotransmitters.</p> Signup and view all the answers

<p>Synapse formation only occurs in the presence of astrocytes or other macroglia, while macroglia are necessary for synapse maintenance.</p> Signup and view all the answers

<p>Extracellular protein signals from astrocytes trigger synapse formation in the CNS.</p> Signup and view all the answers

<p>Astrocytes regulate synapse stability by controlling synapse number, ensuring the appropriate number of synapses are maintained.</p> Signup and view all the answers

<p>Gliotransmitters are released by glia in response to neuronal activity.</p> Signup and view all the answers

<p>Glia, including astrocytes and other macroglia, actively control synaptogenesis by regulating synapse number, stability, and function.</p> Signup and view all the answers

<p>Unequal distribution of ions (Na+, K+, Cl-) across the cell membrane</p> Signup and view all the answers

<p>It pumps 3 Na+ ions out of the cell and 2 K+ ions into the cell, creating a negative charge inside the cell relative to the outside</p> Signup and view all the answers

<p>Between -60 to -80 mV</p> Signup and view all the answers

<p>Glia, specifically astrocytes and other macroglia, play a crucial role in synaptogenesis by regulating synapse formation, stability, and function.</p> Signup and view all the answers

<p>There is evidence that schwann cells in the peripheral nervous system can trigger the formation of neuromuscular junctions.</p> Signup and view all the answers

<p>Glia in culture are able to sense synaptic activity and respond by generating calcium transient currents and releasing gliotransmitters.</p> Signup and view all the answers

<p>Adult hippocampal stem cells also rely on astrocytes for synapse formation, displaying a similar dependence as developing neurons.</p> Signup and view all the answers

<p>The Na+/K+ electrogenic pump actively transports 3 Na+ ions out of the cell and 2 K+ ions into the cell, creating an imbalance of charge across the membrane and contributing to the negative resting membrane potential.</p> Signup and view all the answers

<p>Astrocytes in the CNS have multiple functions, including regulation of extracellular environment around neurons, support and structural maintenance of neurons, formation and maintenance of the blood-brain barrier, release of growth factors to nourish and protect neurons, and clearance of neurotransmitters from synapses.</p> Signup and view all the answers

<p>Synaptic transmission is the process by which an action potential is propagated from the presynaptic neuron to the postsynaptic neuron. The key steps include activation of voltage-gated Ca++ channels in the presynaptic terminal, calcium-dependent priming of synaptic vesicles, exocytosis of neurotransmitters into the synaptic cleft, binding of neurotransmitters to receptors on the postsynaptic membrane, and generation of excitatory or inhibitory postsynaptic potentials in the postsynaptic neuron.</p> Signup and view all the answers