This 2014 German rodent study showed how the thalamus actively controlled and gated information to and from the cerebrum.
In the study’s news coverage, the researchers elaborated on how thalamic control and gating represented a form of memory:
“When asked if, given that
- sensory signals en route to the cortex undergo profound signal transformations in the thalamus,
- a key thalamic transformation is sensory adaptation in which neural output adjusts to the statistics and dynamics of past stimuli, and
- the thalamus, hypothalamus and hippocampus being part of the limbic system,
might memory reconsolidation play a role in the cortico-thalamic pathway?
“It’s conceivable that the cortico-thalamic pathway is subject to long term plasticity,” Groh conjectures. “In fact, on a synaptic level, these inputs can change their strength and retain the adjusted strength for long periods. This process represents another albeit much slower form of adaptation which some interpret as memory.“
Conversely, might the thalamic-cortical pathway affect memory?
“If particular sensory-evoked activity patterns would cause long-term changes in the cortico-thalamic pathway, and thereby change the way incoming signals are processed before reaching the cortex,” he opines, “then this would indeed reflect a form of information storage.“
In other words, there are ways in addition to our usual ideas about memory that the limbic system remembers.
http://www.pnas.org/content/111/18/6798.full “Cortical control of adaptation and sensory relay mode in the thalamus”