Amazing stuff!
"The claustrum is a thin sheet of neurons buried deep within the cerebral cortex. The structure is so small and hidden that neuroscientists once found it very difficult to access, let alone investigate. Now, researchers ... have not only found a way to peer into this enigmatic structure but have also discovered its surprising role in how humans learn and adapt to uncertainties.
In a study ... researchers recorded the activity of the claustrum for the first time in seven patients undergoing epilepsy surgery.
For their epilepsy treatment, the patients had electrodes implanted on various parts of their brains to identify the precise regions that trigger their seizures. Because typical electrodes are too big for the claustrum, the scientists deployed tiny, 40-micrometer wires at the tip of the electrodes that are small enough to target a single neuron. ...
Claustrum neurons have been shown to wrap around the entire brain of a mouse, but data in humans are incomplete. “It is the most connected region of the entire brain, yet it is also extremely easy to miss,” ..."
From the abstract:
"Flexible behavior depends on continuous updating of internal models, yet the neural circuits coordinating this process remain poorly understood.
The claustrum, which is reciprocally connected to nearly the entire neocortex, is uniquely positioned to influence cortical processing.
Here we report single-neuron recordings from the human claustrum during aversive learning, with anterior cingulate cortex and amygdala recordings for comparison.
Claustrum and anterior cingulate neurons displayed structured, task-related responses. Distinct subpopulations encoded stimulus onset and action-contingent outcomes, with outcome representations diverging between regions.
Critically, both regions encoded model-derived latent variables, including uncertainty and prediction error, but with different temporal profiles;
only the anterior cingulate carried uncertainty signals during the intertrial period, whereas both regions encoded uncertainty and prediction error during the active-avoidance period.
By contrast, the amygdala showed minimal latent-variable modulation. These findings provide evidence that human claustrum neurons track higher-order cognitive variables not directly observable from sensory input and reveal dissociable roles for the claustrum and anterior cingulate cortex in tracking latent task states."
Human claustrum neurons encode uncertainty and prediction errors during aversive learning (open access)
Fig. 1: Recording locations and task analysis.
a, MRI brain scans (coronal and axial) coregistered with postoperative CT showing microelectrode locations in the CLA. Red dots indicate microwire positions within the 1-mm-thick CLA. Insets show magnified views of the anterior and middle CLA. The oval depicts a magnified view of the microelectrodes used to record neurons.
Fig. 2: Distribution and timing of CLA and ACC responsive neurons.
No comments:
Post a Comment