Lifeboat Foundation

Summary: Researchers have identified a mechanism within the brain that underlies when we apply stored knowledge to novel decision-making situations.

Source: Max Planck Society.

We regularly find ourselves in new shops or restaurants, we land at airports we don’t know or start a new job. In such situations, the remarkable flexibility of human behavior becomes apparent. Even in new situations, we can often predict the consequences of our actions and thus make appropriate decisions.

Deep within our brain’s temporal lobes, two almond-shaped cell masses help keep us alive. This tiny region, called the amygdala, assists with a variety of brain activities. It helps us learn and remember. It triggers our fight-or-flight response. It even promotes the release of a feel-good chemical called dopamine.

Scientists have learned all this by studying the amygdala over hundreds of years. But we still haven’t reached a full understanding of how these processes work.

Now, Cold Spring Harbor Laboratory neuroscientist Bo Li has brought us several important steps closer. His lab recently made a series of discoveries that show how neurons called somatostatin-expressing (Sst⁺) central amygdala (CeA) neurons help us learn about threats and rewards. He also demonstrated how these neurons relate to dopamine. The discoveries could lead to future treatments for anxiety or drug addiction.

Humans are known to perceive the environment around them differently based on the situation they are in and their own feelings and sensations. Internal states, such as fear, arousal or hunger can thus affect the ways in which sensory information is processed and registered by the brain.

Researchers at Beth Israel Deaconess Medical Center, Boston Children’s Hospital, and Peking University have recently carried out a study investigating the possible effects of serotonin, a neurotransmitter known to regulate sleep, mood, sexual desire, and other inner states, in the processing of visual information. Their findings, published in Neuron, suggest that serotonergic neurons in the brainstem (i.e., the central trunk of the mammalian brain) gate the transfer of visual information from the eyes to the thalamus, an egg-shaped area of the brain.

“Internal states are known to affect sensory perception and processing, but this was generally thought to occur in the cortex or thalamus,” Chinfei Chen, one of the researchers who carried out the study, told Medical Xpress. “One of our previous studies revealed that arousal can suppress certain visual information channels at an earlier stage of the visual pathway–at the connection between the mouse retina and the thalamus, before the information even reaches the brain. This form of ‘filtering’ of information suggests a very efficient means of processing only relevant information.”

A “grand unifying theory” of brain ageing suggests malfunctioning mitochondria might be to blame for Alzheimer’s and other brain conditions. And this new avenue of exploration already has some potential therapies at the ready.

Presented by Madhumita Murgia and John Thornhill, produced by Josh Gabert-Doyon and Edwin Lane. Executive producer is Manuela Saragosa. Sound design by Breen Turner and Samantha Giovinco. Original music by Metaphor Music. The FT’s head of audio is Cheryl Brumley. Special thanks to The Hospital for Sick Children.

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Read a transcript of this episode on FT.com.

A recent study published in the Proceedings of the National Academy of Sciences (PNAS) analyzes structural brain asymmetries in schizophrenia.

Study: Large-scale analysis of structural brain asymmetries in schizophrenia via the ENIGMA consortium. Image Credit: hutpaza / Shutterstock.com

Donald Hoffman and Hannah Critchlow debate the origins of consciousness.

This excerpt was taken from “The key to consciousness,” featuring Sam Coleman, Donald Hoffman, and Hannah Critchlow. Joanna Kavenna hosts.

Continue reading “Does consciousness arise from the brain? | Donald Hoffman challenges Hannah Critchlow” »

One day in the future, we may interact with our electronic devices not with physical input or even voice commands, but simply by thinking about what we want to do. Such brain–computer interfaces (BCIs), combined with machine learning, could allow us to turn our ideas into reality faster and with less effort than ever before — imagine being able to produce a PCB design simply by thinking about how the completed circuit would work. Of course as an assistive technology, BCIs would be nothing less than life-changing for many.

Continue reading “PiEEG Offers Affordable Brain-Computer Interface” »

In the adult brain, synapses are tightly enwrapped by lattices of the extracellular matrix that consist of extremely long-lived molecules. These lattices are deemed to stabilize synapses, restrict the reorganization of their transmission machinery, and prevent them from undergoing structural or morphological changes. At the same time, they are expected to retain some degree of flexibility to permit occasional events of synaptic plasticity. The recent understanding that structural changes to synapses are significantly more frequent than previously assumed (occurring even on a timescale of minutes) has called for a mechanism that allows continual and energy-efficient remodeling of the extracellular matrix (ECM) at synapses. Here, we review recent evidence for such a process based on the constitutive recycling of synaptic ECM molecules. We discuss the key characteristics of this mechanism, focusing on its roles in mediating synaptic transmission and plasticity, and speculate on additional potential functions in neuronal signaling.

An increasing number of studies are showing that synaptic function is strongly influenced by their local environment, including the molecules or cellular components in their vicinity. As a result, the classical synaptic framework (consisting of the pre-and postsynaptic compartments only) has gradually been extended to include the neighboring astrocytic processes (the “tripartite synapse”; Araque et al., 1999) and, ultimately, also the surrounding extracellular matrix (ECM; the “tetrapartite synapse”; Dityatev et al., 2006). Nowadays, the synaptic ECM is recognized to play an essential role in physiological synaptic transmission as well as in plasticity, and its dysregulation has been linked to synaptopathies in a wide variety of brain disorders (Bonneh-Barkay and Wiley, 2009; Pantazopoulos and Berretta, 2016; Ferrer-Ferrer and Dityatev, 2018).