What is a perforant pathway?
The perforant pathway is a large neuronal projection that arises from layers II and III of the entorhinal cortex of the parahippocampal gyrus. These profound alterations effectively disconnect the hippocampal formation from the association and limbic cortices.
What does Perforant mean?
perforant in British English (ˈpɜːfərənt) adjective. anatomy. perforating; esp (of blood vessels) perforating other anatomical structures.
Where does the hippocampus project to?
The hippocampus has direct connections to the entorhinal cortex (via the subiculum) and the amygdala. These structures connect to many other areas of the brain. The entorhinal cortex projects to the cingulate cortex.
What does the entorhinal cortex do?
The entorhinal cortex is the gateway for information entering and leaving the hippocampal formation. The entorhinal cortex is a component of the medial temporal lobe memory system, although it is increasingly believed to have a perceptual function (Baxter, 2009; Suzuki, 2009).
What is the basic circuitry of the hippocampus?
The trisynaptic circuit, or trisynaptic loop is a relay of synaptic transmission in the hippocampus. The trisynaptic circuit is a neural circuit in the hippocampus, which is made up of three major cell groups: granule cells in the dentate gyrus, pyramidal neurons in CA3, and pyramidal neurons in CA1.
What sense travels through the hippocampus?
When you smell something, the sensation travels through your nose, next to the amygdala (which creates emotions) and the hippocampus (where your memories are stored) before ultimately arriving at your thalamus.
What happens when the entorhinal cortex is damaged?
Damage to the entorhinal cortex is common in patients who experience traumatic brain injury, stroke, and Alzheimer’s disease. Entorhinal damage is assumed to interfere with sensory integration; however, substantive knowledge of behavioral patterns is lacking.
Why is the hippocampus so vulnerable?
The hippocampal formation is at the same time a very plastic brain region and a very vulnerable one to insults such as head trauma, ischemia, seizures and severe stress. Circulating glucocorticoids and endogenous excitatory amino acids acting as neurotransmitters play important roles in both aspects.
What are Schaffer collaterals?
Schaffer collaterals are axon collaterals given off by CA3 pyramidal cells in the hippocampus. These collaterals project to area CA1 of the hippocampus and are an integral part of memory formation and the emotional network of the Papez circuit, and of the hippocampal trisynaptic loop.
