The Hippo in the campus Neuro psychiatry Notes

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This is not a post about an actual hippotamus on school premises. But to say the truth, that's probably more interesting than what I am about to discuss.

When we were in university, one of the most difficult courses to comprehend was neurology and its children (neuroanatomy, neuropsychology, and neuropharmacology). But we made it through right? So we'll make it through this post without being a killjoy.


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Let's go back in time

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Back in the 1800s when people wore brown, that's all I can think about when I think about that time...brown stuff. There lived a man named Vladimir Bekhterev, I searched if there was any relationship between him and Putin and so far besides the name, I can't seem to find any.

For the purpose of coolness...Let's call him Vlad.

Vlad had a very sad life from the start. When he was just a child he was the only survivor of tuberculosis in his family. From there he was taken to some medical military facility for schooling, He spent most of his early life in St. Petersburg
where he attended Medicosurgical Academy and trained under one of the most renowned professors at the time, Jan Lucjan Mierzejewski. But this story is not about Jan, it's about Vlad.

Under Jan though, Vlad developed an interest in neuropathology and psychiatry.

After the war Russia fought against the Ottoman Empire, He began working as an intern in Mental health clinics, He later went back to St Petersburg where he first developed an interest in the brain's structure and function.

This is how he became the Hippo on the campus!!! He published several articles, such as his most well-known contribution which was the Pathways of the brain and bone marrow where he outlined the role of the Hippocampus in memory.

What the Hippocampus looks like


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The Hippocampus looks like a seahorse. In fact, the name Hippocampus is derived from Greek translations which mean seahorse.

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One thing that was already known before Vlad came along was the basic anatomy of the organ.

It is located in the temporal lobe of the cerebral hemisphere.

In the brain, the Hippocampus is just a part of the Hippocampal formation and this comprises the Hippocampus, the Hippocampal gyrus, and the Dentate Gyrus. Many schools of thought vary about the rest of the content of this formation.

In the Parahippocampal gyrus, there are areas called the entorhinal cortex and subiculum that help with the flow of information through the Hippocampus.

Parts of the Hippocampus

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Basic circuit of the hippocampus, as drawn by Cajal DG: dentate gyrus. Sub: subiculum. EC: entorhinal cortex

It is subdivided into designated areas with codes. CA1 to CA4.

CA stands for Cornu-ammonis in creation to the fact that the hippocampus in addition to looking like a seahorse also looks like the Ancient Egyptian God's horn Ammon.

It receives information from the rest of the brain through the Peforant Pathway which comes from the Entorhinal cortex and goes to the Dentate gyrus. From the Dentate gyrus, the fibers project to the CA3 region for the Hippocampus.

From CA3 the fibers project to CA1 and then to the Subiculum ( the main output region of the formation) which then goes back to the Entorhinal cortex and then the rest of the brain.

From the Subiculum fibers also travel to the Fonix which connect to the thalamus and hypothalamus (controlling a lot of hormonal and regulatory function).

Functions of the Hippocampus

Vlad was able to find out from a series of experiments that the Hippocampus was important in spacial awareness, and being able to consciously recollect and consolidate memory.

This type of memory is collectible, memory such as facts and events are all parts of the function of the Hippocampus.

Injuries to the Hippocampus have been found to affect a patient's ability to form declarative memory.

There are other types of memory
For example, non-declarative memory is not a function of the Hippocampus but of the Basal ganglia and is more procedural and habitual.

The cells of the hippocampus act collectively as an index in a similar way to a computer retrieval and recalculation process except for the stronger the neural connections, the quicker you'll be able to recall them.

In summary

  • Vladimir Behkhterev's focus in life lead him down the path of Neuropathology.
  • The Hippocampus looks like a seahorse and it is divided into 4 regions from C1 to C4.
  • The Hippocampus is the seat of declarative memory.

Case Presentation

This case presentation comes from NCBI.

It is about a 55-year-old man who presented to the emergency department with a history of acute collapse and a 6-month history of difficulty with memory.

On examination, he was stable, not pale, not cyanosed, afebrile, anicteric, and not dehydrated.

He scores 24/30 on the Montreal Cognitive Assessment.

MRI done showed High intensity in the Temporal area of the brain (where the Hippocampus is located).

A full blood count showed signs of an active infection and this was supported by Microscopy and sensitivity testing. In addition, a Cerebrospinal fluid analysis also showed an active syphilis infection.

PET imaging showed marked uptake of 18F-fluorodeoxyglucose.

He was treated with Penicillin 2.4g every 4 hours for 2 weeks.

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