Are Schaffer collaterals myelinated?

Are Schaffer collaterals myelinated?

We describe a new site for burst initiation in rat hippocampal CA3 neurons: the Schaffer collateral axons. These axons lack myelin, are long, extremely thin, and form synapses along their entire paths, features typical for many, if not most cortical axons in the mammalian brain.

What does the CA3 hippocampus do?

The CA3 region has attracted major attention in recent years for its specific role in memory processes, susceptibility to seizures and neuro-degeneration. Internal connectivity in the CA3 subfield is more rich than in other hippocampal regions.

What is synaptic potentiation?

Abstract. Long-term synaptic potentiation (LTP) is a leading candidate for a synaptic mechanism of rapid learning in mammals. LTP is a persistent increase in synaptic efficacy that can be quickly induced.

What are collaterals in neurons?

An axon typically develops side branches called axon collaterals, so that one neuron can send information to several others. These collaterals, just like the roots of a tree, split into smaller extensions called terminal branches. Each of these has a synaptic terminal on the tip.

What is Perforant path?

The perforant pathway is a large neuronal projection that arises from layers II and III of the entorhinal cortex of the parahippocampal gyrus. It is the principal source of cortical input to the hippocampal formation.

What is CA3 and CA1?

The hippocampus proper refers to the actual structure of the hippocampus which is made up of three regions or subfields. The subfields CA1, CA2, and CA3 use the initials of cornu Ammonis, an earlier name of the hippocampus.

What is the Perforant pathway?

What happens in synapse in LTP?

Long-term potentiation (LTP) is a process involving persistent strengthening of synapses that leads to a long-lasting increase in signal transmission between neurons. It is an important process in the context of synaptic plasticity. LTP recording is widely recognized as a cellular model for the study of memory.

What is a collateral branch of an axon?

Axon Collaterals A collateral branch is an axonal protrusion over10 micrometers in length. These collaterals provide modulation and regulation of the cell firing pattern and represent a feedback system for the neuronal activity. The terminal part of the axon and collaterals tapers progressively.

Where do axon collaterals emerge on a myelinated nerve?

A/P Ch 11

Question Answer
Where do axon collaterals emerge on a myelinated nerve? From the nodes of Ranvier
Which of the following membrane ion channels in the neuron are always open? Leakage channels
Which of the following substances plays the major role in generating the membrane potential of a neuron? Potassium

What does Perforant mean?

(ˈpɜːfərənt) adj. (Anatomy) anatomy perforating; esp (of blood vessels) perforating other anatomical structures.

What does the Papez circuit do?

The Papez circuit /peɪpz/, or medial limbic circuit, is a neural circuit for the control of emotional expression. In 1937, James Papez proposed that the circuit connecting the hypothalamus to the limbic lobe was the basis for emotional experiences.

What is the role of CA1?

CA1 neurons in the human hippocampus are critical for autobiographical memory, mental time travel, and autonoetic consciousness.

What are the two types of synaptic plasticity?

There are two general forms of synaptic plasticity, intrinsic and extrinsic.

  • October 23, 2022