Structure. The subiculum occupies a portion of the parahippocampal gyrus in the mesial temporal lobe and is a component of the medial temporal memory system. It is made up of several cortical fields and for this reason is sometimes referred to as the subicular complex.

What does the hippocampus do?

Hippocampus is a complex brain structure embedded deep into temporal lobe. It has a major role in learning and memory. It is a plastic and vulnerable structure that gets damaged by a variety of stimuli. Studies have shown that it also gets affected in a variety of neurological and psychiatric disorders.

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 hippocampal formation?

The hippocampal formation is a prominent C-shaped structure bulging in the floor of the temporal horn of the lateral ventricle. ... The other regions that together comprise the hippocampal formation consist of the dentate gyrus, the subicular complex, and the entorhinal cortex.

What is the 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. It is the principal source of cortical input to the hippocampal formation.

2-Minute Neuroscience: The Hippocampus

What does Perforant mean?

perforant in British English

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

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 is hippocampal sulcus?

The hippocampal sulcus is the inferior lateral extension of the transverse fissure (of Bichat), which in turn communicates with the ambient cistern. It is a shallow groove on the medial surface of the hippocampus, between the dentate gyrus and subiculum, inferior to the fimbria and fimbriodentate sulcus ¹.

What is brain fornix?

The fornix (plural: fornices) is the main efferent system of the hippocampus and an important part of the limbic system. It is one of the commissural fibers connecting the cerebral hemispheres.

What is the difference between hypothalamus and hippocampus?

The hypothalamus controls emotions. It also regulates your body's temperature and controls crucial urges — such as eating or sleeping. The hippocampus sends memories to be stored in appropriate sections of the cerebrum and then recalls them when necessary.

What is in the entorhinal cortex?

The entorhinal cortex (EC) is an area of the brain's allocortex, located in the medial temporal lobe, whose functions include being a widespread network hub for memory, navigation, and the perception of time. The EC is the main interface between the hippocampus and neocortex.

What is entorhinal cortex and hippocampus?

The entorhinal cortex (EC)–hippocampal (HPC) network plays an essential role for episodic memory, which preserves spatial and temporal information about the occurrence of past events. ... Episodic memory enables us to remember where and when a distinct sequence of events occurred in our past.

What does entorhinal mean?

: of, relating to, or being the part of the cerebral cortex in the medial temporal lobe that serves as the main cortical input to the hippocampus.

What is amygdala and hippocampus?

The amygdala is specialized for input and processing of emotion, while the hippocampus is essential for declarative or episodic memory. During emotional reactions, these two brain regions interact to translate the emotion into particular outcomes.

What emotions does the hippocampus control?

The hippocampus, located in the medial temporal lobe and connected with the amygdala that controls emotional memory recalling and regulation (Schumacher et al., 2018); it has increased the functional connectivity with anterior cingulate or amygdala during emotional regulation and recalling of positive memory (Guzmán- ...

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.

Why is the fornix important?

The fornix acts as the major output tract of the hippocampus, arcing around the thalamus and connecting the medial temporal lobes to the hypothalamus. The fornix plays an important role in the formation and consolidation of declarative memories and is an important component of the classic Papez circuit.

How does a fornix work?

Fornix is the main output tract of the hippocampus. Its main function is to transmit the information from the hippocampus to the mammillary bodies and the anterior nucleus of thalamus. The commissure of the fornix also serves to connect the two hippocampal formations.

Where is fornix located?

The fornix originates in the hippocampus, where it emerges from a collection of fibers called the fimbria. It then stretches up and around the thalamus toward the front of the brain. When it reaches a tract called the anterior commissure, it branches downward.

What is the collateral sulcus?

The collateral sulcus is in the ventromedial surface of the temporal lobe, and it defines where the outer reaches of the hippocampal complex are located. This region includes entorhinal, perirhinal, and parahippocampal cortical areas.

Where is the choroid fissure?

The choroidal fissure, or choroid fissure, is a cleft of the medial surface of the cerebral hemisphere running immediately above the hippocampus and forms the medial wall of the lateral ventricle and attachment site for the choroid plexus.

Where is the Rhinal sulcus?

The rhinal sulcus is located on the anteromedial surface of the temporal lobe. It curves in an anteroposterior direction and separates the uncus from the temporal pole.

What is a synaptic?

A synapse is the small gap between two neurons, where nerve impulses are relayed by a neurotransmitter from the axon of a presynaptic (sending) neuron to the dendrite of a postsynaptic (receiving) neuron. It is referred to as the synaptic cleft or synaptic gap.

What causes synaptic potentiation?

Long-term potentiation (LTP) is a persistent strengthening of synaptic connections induced by a brief period of high-frequency presynaptic activity. ... Parallel fiber LTP is initiated by presynaptic calcium influx through voltage-activated calcium channels.

What is meant by synaptic transmission?

Definition. Synaptic transmission is the biological process by which a neuron communicates with a target cell across a synapse. Chemical synaptic transmission involves the release of a neurotransmitter from the pre-synaptic neuron, and neurotransmitter binding to specific post-synaptic receptors.