Hormones and Memory

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Hormones and Memory
A seminar on the effects of hormones on memory
By Hamish Whistler
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Hormones Role in the Body
Hormones and Memory

• Like all other living creatures of this world, we
  are made up of living cells that interact with
  each other mainly through chemical means.
• Hormones are regulating chemicals in the body,
  their complex interaction with organs and cells
  help shape our bodies, behaviour and the way we
  think.
• One such effect is that of the role of hormones
  and their interaction with our memory

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Stress Hormones and Memory
Hormones and Memory

• The Pituitary Adrenal Axis
• Cells in the hypothalamus secrete CRF
  (Corticotrophin Releasing Factor) in stressful
  situations.
• The CRF is transported to the Anterior Pituitary
• The Anterior Pituitary is stimulated to produce
  ACTH (Adrenocorticotropic Hormone)
• ACTH controls the Adrenal Cortex and stimulates
  it to produce Cortisol.

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Stress Hormones and Memory
Hormones and Memory

• The Pituitary Adrenal Axis (continued)
• Cortisol exerts a negative feed back effect on
  the hypothalamus that inhibits further release of
  CRF by the hypothalamus
• The cycle continues on until the hypothalamus
  stops producing CRF i.e. the stressful situation
  as passed.

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Stress Hormones and Memory
Hormones and Memory
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Stress Hormones and Memory
Hormones and Memory

• Glucocorticoids (cortisol and corticosterone)
• A study by Newcomer et al (1999) showed that high
  doses of Cortisol (suggesting high levels of
  stress) can have a negative impact on verbal
  declarative memory.

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Stress Hormones and Memory
Hormones and Memory

• Glucocorticoids (cortisol and corticosterone)

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Stress Hormones and Memory
Hormones and Memory

• Example Implications The exam room
• In examination settings we often stress and reach
  high levels of arousal, this could lead to a
  detrimental effect on recall in exam performance.
  
• In the situation of an exam, not being able to
  remember can stress you further starting a
  downwards cycle into a memory block, doing easier
  questions first and calming down the best way
  out.
• More mild amounts of stress are shown to have
  minimal or insignificant effects on performance,
  some arousal may even be better for memory recall.

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Estrogen and Memory
Hormones and Memory

• It is usually more of a concern to woman reaching
  menopause whose natural production of estrogen
  runs out when their ovaries stop functioning
• Men convert testosterone into estrogen in the
  brain and therefore never normally totally run
  out
• One effect of menopause mentioned by woman is the
  reduction in memory performance
• This is also reported by men with prostate cancer
  who have had their testosterone levels dropped to
  treat the cancerSee a trend?

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Estrogen and Memory
Hormones and Memory

• Research towards woman
• Decline in memory is usually in source memory and
  some verbal declarative memory, not so much item
  memory.
• Research in long term estrogen replacement
  therapy in woman suggest that estrogen use (when
  combined with progesterone) may temper
  age-related cognitive decline by helping to
  maintain functions typically used in the frontal
  lobes.

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Estrogen and Memory
Hormones and Memory

• Research towards woman continued
• Further more conclusive research and research
  into other areas of memory are underway but is
  based on longitudinal studies and results will
  not be available for a few years.

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Estrogen and Memory
Hormones and Memory

• Alzheimer's disease and woman
• Estrogen treatment has also given successful
  results in the treatment of Alzheimers disease,
  making symptoms less severe and if taken before
  the onset of, used as a preventative.
• Brain cells that are often damaged from
  Alzheimers disease have been discovered to have
  receptors for estrogen and nerve-growth-factor
  suggesting an interaction of the two.

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Estrogen and Memory
Hormones and Memory

• Research towards men
• Men with prostate cancer which have had their
  testosterone levels reduced for cancer treatment
  have received estrogen therapy and have had
  improvements on verbal memory but not on working
  memory.
• Very little research has been done in this area
  (that I could find) and it is only the
  beginnings.

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Estrogen and Memory
Hormones and Memory

• Research towards animals
• Research in mice has shown that estrogen enhances
  the formation of dendrites and axons between
  brain cells
• The roll of estrogen is still not clear, most
  studies suggest it has more to do with particular
  memory aspects. An example is social recognition
  memory in mice.

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Estrogen and Memory
Hormones and Memory

• Research towards animals Continued
• One study showes doses of Estrogen to give two
  fold increases in spines (dendrites and axons) as
  shown in the left slide versus normal spines
  growth in the right slide in brain cells taken
  from a rat embryo.

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Closing Notes
Hormones and Memory

• Most of the research in these areas is new and
  controversial, many studies contradict each other
  etc.
• Further research will expose the wider range of
  hormones interacting and allow for better
  diagnosis and treatments of disorders to become
  available.
• Its not a matter of if, but rather when
• Thank you to those of you still awake for
  listening
• THE END