Neuroanatomy, Hippocampus (2023)

FAQs

What is the Neuroanatomy of the hippocampus? ›

The hippocampus is a convex elevation of gray matter tissue within the parahippocampal gyrus inside the inferior temporal horn of the lateral ventricle. One can describe it more holistically as a curved and recurved sheet of the cortex that folds into the temporal lobe's medial surface.

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.

Being an integral part of the limbic system, hippocampus plays a vital role in regulating learning, memory encoding, memory consolidation, and spatial navigation.

The hippocampus is the structure in the brain most closely aligned to memory formation. It is important as an early storage place for long-term memory, and it is involved in the transition of long-term memory to even more enduring permanent memory.

The hippocampus and dentate gyrus are actually cortex, but it is 3-layered cortex rather than 6-layered cortex as in the neocortex.

The hippocampus, as the medial pallium, is a structure found in all vertebrates. In humans, it contains two main interlocking parts: the hippocampus proper (also called Ammon's horn), and the dentate gyrus.

Aerobic exercise in particular helps boost BDNF levels and promote hippocampal function. Another study showed that light and moderate exercise increased the size of the hippocampus and enhanced memory retention.

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- ...

Damage to the hippocampus can cause a condition called amnesia that prevents people from forming new memories and remembering past experiences.

In short, the hippocampus orchestrates both the recording and the storage of memories, and without it, this “memory consolidation” cannot occur. After his memory vanished, H.M. lost his job and had no choice but to keep living with his parents.

How does the hippocampus store memory? ›

When a memory is created, information flows from the cortex, the part of the brain rich in nerve cells, to the hippocampus, the central switching point for memories in the brain. The information flows in the opposite direction when we retrieve a memory.

Because the brain is lateralized and symmetrical, you actually have two hippocampi. They are located just above each ear and about an inch-and-a-half inside your head.

Hippocampal activity seems to specifically support memory consolidation during sleep, through specific coordinated neurophysiological events (slow waves, spindles, ripples) that would facilitate the integration of new information into the pre-existing cortical networks.

The amygdala and the hippocampus are two brain structures involved in fear and traumatic stress. The amygdala detects whether a stimulus (person or event) is threatening and the hippocampus, the center of short-term memory, links the fear response to the context in which the threatening stimulus or event occurred.

Systematic mining of published data on axonal and dendritic profiles, augmented with information on neurotransmitter and synaptic specificity, led to the tentative definition of over 100 distinct neuron types across the hippocampal formation.

Within the hippocampal memory system, CA1 neurons are critically involved the formation, consolidation, and retrieval of hippocampal-dependant memories. Recent high-resolution volumetry did show an association between CA1 volume and episodic memory retrieval (38).

The hippocampus is thought to be principally involved in storing long-term memories and in making those memories resistant to forgetting, though this is a matter of debate. It is also thought to play an important role in spatial processing and navigation.

The hippocampus is a small region of the brain that forms part of the limbic system and is primarily associated with memory and spatial navigation.

Growth hormone is produced within the hippocampus where it responds to age, sex, and stress.

Does anxiety activate the hippocampus? ›

Growing evidence indicates that anxiety is associated with increased neuronal excitability in the hippocampus, and alterations in local regulation of hippocampal excitability have been suggested to underlie behavioral disruptions characteristic of certain anxiety disorders.

It's also known that the hippocampus sends signals to other areas of the brain—the amygdala and the hypothalamus—that have also been shown to control anxiety-related behavior.

The region in question is the cingulate gyrus, also referred to as 'limbic cortex', particularly in non-primate mammals where its differentiation is less well developed.

Our results indicate that stimulation of the hippocampus during encoding helped to build strong associative memories and enhanced recollection in subsequent trials. Moreover, stimulation significantly increased theta power in the lateral middle temporal cortex during successful memory encoding.

Research shows that we have the capacity to grow new neurons above and beyond what is generally produced in our hippocampus and to make them become mature and strong within weeks and months. The best way to generate new hippocampal neurons is to exercise.

Chronic stress can cause long-term damage to the hippocampus. In fact, the hippocampus itself has been shown to shrink in size in people suffering from an ongoing HPA axis stress response.

Researchers have found that traumatic events and severe stress can cause shrinkage of this area of the brain, with significant changes observed in both men and women who suffer from Post-Traumatic Stress Disorder as the result of sexual assault or combat.

Stress, memory, and the hippocampus: can't live with it, can't live without it.

One of the biggest risks of the hippocampus removal is the recurrence of seizures, which happens when some parts of the hippocampus and amygdala are not removed. This may mean the patient has to go through another round of surgery.

What happens to the hippocampus due to a lack of sleep? ›

Because the formation of object-location memories critically depends on proper hippocampal function [23],these findings indicate that sleep deprivation leads to memory deficits by misregulating cAMP signaling in hippocampal excitatory neurons.

Sleep deprivation impairs hippocampal synaptic plasticity. Sleep deprivation is detrimental to hippocampus-dependent memory. As the neural correlate of learning and memory, it is not surprising that sleep deprivation disrupts synaptic plasticity in the hippocampus as well.

Substantial evidence suggests that one of the main targets of alcohol toxicity in the brain is the hippocampus; indeed the alcoholic population shows neuronal loss and a reduction in total hippocampal volume as shown by magnetic resonance imaging (Jernigan et al., 1991; Harper, 1998).

Deep inside the temporal lobe of the brain, the hippocampus has a central role in our ability to remember, imagine and dream.

Love makes your brain light up!

MRI scans also indicated that the reward circuit—the amygdala, the hippocampus, and the prefrontal cortex—which is very sensitive to behaviours that induce pleasure, lights up on brain scans when talking about a loved one because of increased blood flow in these areas.

Right hippocampus plays a critical role in spatial memory in older adults, while the role of left hippocampus in verbal memory is more prominent.

Although it is often referred to in the singular, there are actually two hippocampi in the human brain—one in each cerebral hemisphere. The two hippocampi are connected via the fornix, which is a C-shaped bundle of nerve fibers that connect the hippocampi together, as well as with other structures in the brain.

Depression causes the hippocampus to raise its cortisol levels, impeding the development of neurons in your brain. The shrinkage of brain circuits is closely connected to the reduction of the affected part's function. While other cerebral areas shrink due to high levels of cortisol, the amygdala enlarges.

Like many parts of the brain's limbic system, the hippocampus is involved in memory, learning, and emotion. Its largest job is to hold short-term memories and transfer them to long-term storage in our brains. It also plays a role in emotional processing, including anxiety and avoidance behaviors.

After reviewing the available data regarding the various effects of manipulating (e.g. lesions, chemical or electrical stimulation) the hippocampal formation, Jarrard concluded that this structure likely played a role in motivated behaviors, specifically in general behavioral activation and incentive motivation.

What is the neuroanatomy of the brain? ›

Neuroanatomy is the study of the relationship between structure and function in the nervous system. Neuroanatomy includes the study of macroscopic and microscopic structures. Macroscopic structures are larger structures, such as folds of the brain.

Neuroanatomy is the careful description of all of the anatomical structures in the nervous system. This includes all of the major and minor structures in the brain, the spinal cord and the nerves, the sensory and motor nerves as well as neurons and glia.

Neuroanatomy uses primarily visual techniques to investigate neural structure with the motivation of deducing and formulating general organizational principles, mechanisms, and structural–functional correlations.

arteries supplying spinal cord. spinal nerves forming cauda equina. cranial nerve attached to the medulla oblongata. cranial nerve nuclei located in medula oblongata.

Study Tip Neuroanatomy 1.

First of all: Visualize neuroanatomy. Teaching assistants(=mentors) have passed the first course successfully and have spent a lot of time visualizing the neuroanatomy. Visualize in a way that you enjoy and 'll simultaneously learn as you have fun making the visualization.

Lobes of the Brain and What They Control

Each brain hemisphere (parts of the cerebrum) has four sections, called lobes: frontal, parietal, temporal and occipital. Each lobe controls specific functions.

A neuron has three main parts: dendrites, an axon, and a cell body or soma (see image below), which can be represented as the branches, roots and trunk of a tree, respectively. A dendrite (tree branch) is where a neuron receives input from other cells.

The limbic system controls the experience and expression of emotions, as well as some automatic functions of the body. By producing emotions (such as fear, anger, pleasure, and sadness), the limbic system enables people to behave in ways that help them communicate and survive physical and psychologic upsets.

The Cerebellum

This area of the brain is responsible for fine motor movement, balance, and the brain's ability to determine limb position.

What part of the brain controls smell? ›

Smells are handled by the olfactory bulb, the structure in the front of the brain that sends information to the other areas of the body's central command for further processing. Odors take a direct route to the limbic system, including the amygdala and the hippocampus, the regions related to emotion and memory.

In a nutshell, then, the biggest unsolved problem is how the brain generates the mind, conceived of in a way that does not simultaneously require answering the problem of consciousness (Box 1).

The nervous system includes the brain, spinal cord, and a complex network of nerves. This system sends messages back and forth between the brain and the body. The brain is what controls all the body's functions. The spinal cord runs from the brain down through the back.

The key to performing an efficient neurological examination is observation. More than half of the neurological examination is performed by simply observing the patient – how he/she speaks, thinks, walks, moves, and simply interacts with the examiner.