A summary of my college research in Neuroscience

15th September 2017
Posted in Blog
15th September 2017 geri

A summary of my college research in Neuroscience

Aim:

To investigate the potential role of neurotrophins in the pathophysiology of depression and their potential as a therapeutic target

 

Depression:

Depression is a chronic, debilitating psychiatric disorder characterized by feelings of sadness and despair. The incidence of depressive illness is growing across the developed (and increasingly in the developing) world and is a major cause of mortality worldwide. According to the World Health Organisation, by the year 2020, depression will be second only to heart disease as the leading cause of disability worldwide. The World Health Organisation estimates the total economic cost of depression in Europe to be 128 billion euro annually while the economic burden in the United States is estimated at $80 billion annually. These direct and indirect costs are associated with sick leave and productivity losses, outpatient care, hospitalisation, pharmacological treatment and mortality.

 

Antidepressants:

Although it is more than sixty years since the development of the first treatments for this debilitating mental illness, the precise mechanism of therapeutic action of antidepressant drugs is currently not clearly understood. This is due to the involvement of such a variety of intracellular pathways and signalling transduction cascades in the pathophysiology and treatment of depression.

 

The Hippocampus:

The hippocampus is implicated as one of most important brain structures involved in depression. Chronic stress and resultant depression can lead to atrophy or loss of hippocampal neurons. There are numerous reports demonstrating that the volume of the hippocampus is decreased in depressed subjects. The hippocampus also shares anatomical connections with the amygdala and prefrontal cortex, two very important brain areas implicated in mood and cognition. Early childhood events and adult stress have been shown to induce neurodegenerative alterations in the brain, such as a reduction in size of the hippocampus and the pre-frontal cortex.

 

The neurotrophin hypothesis of depression:

The plasticity hypothesis was proposed in 1997 and demonstrated a role for neurotrophic factors in stress actions. They found that a single or repeated exposure to stress rapidly decreased the expression of brain-derived neurotrophic factor (BDNF). As previously mentioned, BDNF effects on the nervous system are vast and include outgrowth of neurites, differentiation, synaptic connectivity, neuronal repair, neuronal transmission and protection against stress-induced neuronal damage.

Studies at the clinical level of chronic stress and depression have shown decreased BDNF expression in the hippocampus and cerebral cortex and a resultant decrease in neurogenesis. Decreased BDNF in depressed patients perhaps underpin the atrophy and resultant decrease in brain volumes of certain limbic structures, including the prefrontal cortex, hippocampus and the amygdala that have been observed in depressed patients.

The neurotrophin hypothesis of depression is based on a downregulation of central brain-derived neurotrophic factor (BDNF) and a reduction in BDNF associated neuronal survival activities underlying the pathogenesis of depression eventually this may result in a breakdown and deregulation of neuronal networks involved in the regulation of mood. This implicates Brain Derived Neurotrophic Factor as a link between stress, neurogenesis and hippocampal atrophy in depression.

 

Conclusion:

In my studies, a decrease in BDNF expression was observed in the hippocampus of depressed induced pre-clinical models, and this decrease was prevented by chronic desipramine treatment.

 

Comments (4)

  1. James

    Well written the human brain is like a brain in a car if there’s a fault it will not function properly and has to be ‘re mapped .but some one that has brain or spinal injury the brain sences that all the nerve endings are sending back different messages .

    This the way I see it like depression. 90% of people don’t need antidepressants as the can lead a person to suicide. Physicharist are quick to prescribe antidepressants .a good physcicolgist is better at getting to the bottom of the cause..and it also helps to take the person out and away from what the problem is and another thing very important is the food we eat if we eat junk food and our body reacts to it like an allergy it sends messages to the brain and the brain network all the menninges nerve endings become inflamed and brain closes down .and yes we feel down and depressed..
    Geri is a very brave girl for what she has come through .I love this girl❤ .she’s a fighter and refuses to give up. Them comments are my own. Support Geri in her blog

  2. Tim

    Hi Geri,
    I’m glad to see your new blogs (I left a message here a few weeks back on ‘the plus-es of being on one’s own’).

    I see you mentioned the plasticity of different parts of the brain – so you may have come across those studies that showed that regular deep meditation over (5, 10, 15?) years can make changes in the brain’s structure.

    I am not a meditator – although God knows I’ve tried-).

    I find (again) immersing myself in my interests *for their own sake – and not for a goal* is relaxing enough.

    On the point of meditation – the old old ‘skill’ of reverie – e.g. gazing through one’s window at the back garden for half an hour or so – we are losing it through busy, noisy phones – and if we don’t switch off – we will never have time to create or process the day so far.

    That always made sense – but now science has proven it (ahem).

    I liked your piece on the benefits of sport. Even a 30 or 45 minute walk in the fresh air daily has always made sense – and the times I was deep in myself – I had to make myself do it. Why has discipline become a bad word?

    Another book which I read maybe 10 years back when it first came out – spoke of the benefits of more natural treatments for illnesses (mainly anxiety and depression maybe OCD) – was called “Healing Without Freud or Prozac” – the author’s name escapes me – he was a French psychiatrist practicing in America (probably Faber & Faber published it).

    These treatments did include exercise – plus the benefits of having a pet.

    Good luck in finding a place for yourself.

    Best wishes

    Tim

    • geri

      Thanks for your support Tim and your continued reading of my blogs, I appreciate it and your invaluable feedback!

      Geri

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