I find this question very interesting, for this reason i did some digging.
Short answer
Yes, there're many studies about neurobiological implication of "repressed memories" and they underline how informations do not disappear. Through the
mechanisms of complex neural processes, it is obvious that this information is exposed to various kinds of cellular and molecular operations. These processes can not be deleted. The brain never “forgets” at the cellular and molecular levels.(Mehmet Emin Ceylan, M.D., Aslıhan Sayın, M.D., 2012)
Long answer
In recent years, an effort has been made to identify the underlying neuroanatomical,
neurophysiological and molecular underpinnings of psychoanalytical concepts like repression. The view that, every mental action is caused by a change in an
identifiable neural system (or vice versa), is not surprising. Any decision we make, any
feeling we have, is the result of activity in neural networks and molecular-level structures
such as receptors, messenger systems, neurotransmitters etc. that are involved in the process
of neurotransmission. Moreover, this fact applies not only to conscious mental activities, but
also to mental activities that are not conscious. Everything that goes on in the brain affects our
mind, but we are not consciously aware of everything that goes on in our mind. This situation
is described by Freud as the equivalent of an unconscious mental process.
We know that repression is a defense mechanism that plays a role in the formation of
unconscious mental activities and processes. Thus, it is reasonable to assume that repression
must have a neural mechanism. The technology of Freud’s time was incapable of explaining
the biological correlates of the mental processes described by his psychoanalytic theory.
Today’s technological capabilities, advances in brain imaging methods, advanced methods in
brain electrophysiology and molecular biology promise an opportunity to observe and analyze
these mechanisms.
- Neural representation of the external event is bound by hippocampus
- Then, the LTP (long-term potentiation) process provides the neural mechanisms of consolidation, in which a
particular external event becomes a lasting memory, which is the basis for long-term memory.
- While the hippocampus controls consciouss memory,the amygdala is required for the
unconsciously associated vegetative reaction (Bechara et al., 1995).
- fMRI studies in post-traumatic
stress disorder patients indicate that recall of traumatic events is associated with an increased
activation of the amygdala and a reduced activation of the hippocampus
- It is reasonable to assume that repression
must have a neural mechanism: The following study suggests that dorsolateral prefrontal cortex,
and especially its caudal part plays a major role for repression of childhood traumatic events.
Possible molecular mechanism of memory erasure in repression is long term depression of
glutamatergic neurotransmission between prefrontal cortex- thalamus- limbic system.
REFERENCES
Neurobiology of Repression
Bechara, A., Tranel, D., Damasio, H., Adolphs, R., Rockland, C., Damasioa, A.R.,
1995. Double dissociation of conditioning and declerative knowledge relative to the amigdala
and hippocampus in humans. Science 269, 1115-1118.
