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 is the function of Cornu Ammonis?

Disrupted Functional Connectivity of Cornu Ammonis Subregions in Amnestic Mild Cognitive Impairment: A Longitudinal Resting-State fMRI Study. Background: The cornu ammonis (CA), as part of the hippocampal formation, represents a primary target region of neural degeneration in amnestic mild cognitive impairment (aMCI).

Where is the Cornu Ammonis located?

The Cornu Ammonis (CA) subfield forms the area between dentate gyrus and the subiculum. It is subdivided into CA3, CA2 and CA1, according to the nomenclature of Lorente de Nó. The polymorphic layer of the dentate gyrus is sometimes referred to as CA4, also defined by Lorente de Nó.

What does CA in hippocampus mean?

The hippocampus, in the temporal lobe, is phylogenetically one of the oldest parts of the brain and forms part of the limbic system. The hippocampus proper is defined by the dentate gyrus and Cornu Ammonis (CA). Internal connectivity in the CA3 subfield is more rich than in other hippocampal regions.

What are recurrent collaterals?

a negative-feedback system that prevents rapid, repeated firing of the same motor neuron. To accomplish this, one branch of an axon loops back toward the cell body of the neuron and communicates with an inhibitory Renshaw cell. The Renshaw cell in turn inhibits the neuron.

What are recurrent collaterals in the hippocampus?

A recurrent collateral makes several thousand contacts with a much larger target population. Mossy fiber boutons contact proximal apical dendrites of CA3 pyramidal cells and have a diameter of 4–8 μm.

What is the role of subiculum?

Functions of the Subiculum The subiculum is an integral part of the limbic memory system, responsible for memory retrieval (22) and spatial encoding (23–26). Similar to CA1 neurons, subicular neurons are place cells that respond when the animal is in a particular location in space.

What is DG in hippocampus?

The dentate gyrus (DG) is part of the hippocampal formation in the temporal lobe of the brain, which also includes the hippocampus and the subiculum.

What are CA1 neurons?

Although hippocampal cornu ammonis (CA1) neurons in rodents play a pivotal role in the processing of hippocampus-dependent memory, the contribution of CA1 neurons in the human hippocampus to autobiographical memory and autonoetic consciousness remains elusive because of the rareness of a human model (10).