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Dentate gyrus

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Dentate gyrus

What is the dentate gyrus?

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The dentate gyrus is a key part of the hippocampal formation, which plays a crucial role in memory formation and spatial navigation. It is one of the few regions in the adult brain where Neurogenesis (the formation of new neurons) occurs throughout life. The dentate gyrus is thought to contribute to the formation of new episodic memories, the spontaneous exploration of novel environments, and the processing of spatial information.

Structurally, the dentate gyrus is located in the medial Temporal lobe of the brain, forming a C-shaped layer of densely packed neurons. It receives inputs primarily from the Entorhinal Cortex through the perforant path and sends its outputs to the CA3 region of the hippocampus via the mossy fibers. This connectivity is essential for the hippocampal trisynaptic circuit, which is involved in the processing and consolidation of information.

Functionally, the dentate gyrus is involved in pattern separation, a process by which similar experiences or events are transformed into distinct, non-overlapping representations. This is believed to be crucial for the ability to distinguish between similar but not identical environments or contexts, thereby reducing interference between memories and contributing to more precise memory recall.

In summary, the dentate gyrus is a critical component of the hippocampal formation, involved in memory formation, spatial navigation, and neurogenesis, playing a key role in pattern separation and the processing of spatial information.****

LTP in dentate gyrus of a rabbit

Long-lasting potentiation of synaptic transmission in the dentate area of the anesthetized rabbit following stimulation of the perforant path. Journal of Physiology, 232, 331-356. Abstract

  1. The after-effects of repetitive stimulation of the perforant path fibers to the dentate area of the hippocampal formation have been examined with extracellular micro-electrodes in rabbits anesthetized with urethane.
  2. In fifteen out of eighteen rabbits the population response recorded from Granule cells in the dentate area to single perforant path volleys was potentiated for periods ranging from 30 min to 10 hr after one or more conditioning trains at 10-20/sec for 10-15 sec, or 100/sec for 3-4 sec.
  3. The population response was analyzed in terms of three parameters: the amplitude of the population excitatory post-synaptic potential (EPSP), signaling the depolarization of the granule cells, and the amplitude and latency of the population spike, signaling the discharge of the granule cells.
  4. During conditioning at 10-20/sec there was massive potentiation of the population spike (‘frequency potentiation’). The spike was suppressed during stimulation at 100/sec. Both frequencies produced long-term potentiation.
  5. The results suggest that two independent mechanisms are responsible for long-lasting potentiation: (a) an increase in the efficiency of synaptic transmission at the perforant path synapses; (b) an increase in the excitability of the granule cel population.
    Source: Dentate gyrus

see also

Tags: neurobiology science gehirnregion
Superlink: 051 ☣Neurobiology 050 🧠Neuroscience
Hippocampus

Source

Journal of Physiology, 232, 331-356. Abstract, Bliss, T. V. P. & Lømo, T. (1973)

Created: 14-10-24 16:18