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The first study of bottlenose dolphins’ sensitivity to electric fields has found some can detect electric direct current (DC) fields as weak as 2.4 microvolts per centimeter, even better than the measured capacities of platypus. Although still less capable in this regard than sharks and rays, the finding suggests electroreceptivity may play a more important role in dolphins’ survival than previously suspected.

Dolphins have small pits rich in nerve endings on their face, known as vibrissal crypts. A 2022 study confirmed these allow them to detect weak electric fields, but provided no indication on how weak that can be. It makes sense for species that live in murky rivers or estuaries to develop alternatives to seeing underwater, but for those dolphins that inhabit clearer waters such capacities might prove superfluous.

However, it seems even in their frequently crystal-clear waters bottlenose dolphins find electrosensitivity useful enough they have maintained it to a considerable degree.

Source: Northwestern University.

Scientists have discovered a new neural pathway involved in how the brain encodes the transition to high-intensity fear response behaviors that are necessary for survival, according to a recent study published in Nature.

Jones Parker, Ph.D., assistant professor of Neuroscience, of Pharmacology and of Psychiatry and Behavioral Sciences, was a co-author of the study.

Summary: If neural assemblies between the hippocampus and prefrontal cortex fail to sync together at the correct time, memories are lost.

Source: University of Bristol.

Learning, remembering something, and recalling memories is supported by multiple separate groups of neurons connected inside and across key regions in the brain. If these neural assemblies fail to sync together at the right time, the memories are lost, a new study led by the universities of Bristol and Heidelberg has found.

Summary: In people with PTSD, during REM sleep norepinephrine and serotonin levels remain high, reducing the brain’s ability to inhibit fear-expression neurons through neural rhythms sent between the prefrontal cortex and amygdala. Those with PTSD require higher frequency rhythms to extinguish fear memories. Researchers say unlocking the higher frequencies via therapies could help to restore quality sleep in those with PTSD.

Source: Virginia Tech.

During periods of rapid eye movement (REM) sleep, brain activity often resembles that of awake behavior. At times, the brain can actually be more active during REM sleep than when you’re awake. It’s why REM sleep is sometimes called “paradoxical sleep,” said Virginia Tech neuroscientist Sujith Vijayan.

Summary: Postmortem brains of those with schizophrenia have fewer genes associated with 12-hour activity cycles in the dorsolateral prefrontal cortex. Mitochondrial-related genes in the dlPFC did maintain a 12-hour rhythm, but their activity did not peak at normal times.

Source: PLOS

Researchers at the University of Pittsburgh School of Medicine, U.S. present the first evidence of 12-hour cycles of gene activity in the human brain.

Summary: Rhythmic bursts of activity in the prefrontal cortex reduce variability as an animal focuses on a task.

Source: picower institute for learning and memory.

Working memory, that handy ability to consciously hold and manipulate new information in mind, takes work. In particular, participating neurons in the prefrontal cortex have to work together in synchrony to focus our thoughts, whether we’re remembering a set of directions or tonight’s menu specials.

Summary: Extended intense cognitive work causes potentially toxic byproducts to build up in the prefrontal cortex. This alters control over decision-making, causing a shift toward low-cost actions that require less effort as cognitive fatigue sets in.

Source: Cell Press.

It’s no surprise that hard physical labor wears you out, but what about hard mental labor? Sitting around thinking hard for hours makes one feel worn out, too.

Summary: AgRP neurons in the hypothalamus play a critical role in shaping the structure and function of the prefrontal cortex in mice. The findings shed light on how the prefrontal cortex is altered in disorders such as schizophrenia.

Source: Yale.

The prefrontal cortex region of the human brain is responsible for a range of complex functions from decision-making to certain types of memory.