Multiple neurocognitive systems contribute simultaneously to learning. For example, dopamine and basal ganglia (BG) systems are thought to support reinforcement learning (RL) by incrementally updating the value of choices, while the prefrontal cortex (PFC) contributes different computations, such as actively maintaining precise information in working memory (WM). It is commonly thought that WM and PFC show more protracted development than RL and BG systems, yet their contributions are rarely assessed in tandem. Here, we used a simple learning task to test how RL and WM contribute to changes in learning across adolescence. We tested 187 subjects ages 8 to 17 and 53 adults (25-30). Participants learned stimulus-action associations from feedback; the learning load was varied to be within or exceed [...]
Variation in early life maternal care predicts later long range frontal cortex synapse development in mice
Empirical and theoretical work suggests that early postnatal experience may inform later developing synaptic connectivity to adapt the brain to its environment. We hypothesized that early maternal experience may program the development of synaptic density on long range frontal cortex projections. To test this idea, we used maternal separation (MS) to generate environmental variability and examined how MS affected 1) maternal care and 2) synapse density on virally-labeled long range axons of offspring reared in MS or control conditions. We found that MS and variation in maternal care predicted bouton density on dorsal frontal cortex axons that terminated in the basolateral amygdala (BLA) and dorsomedial striatum (DMS) with more, fragmented care associated with higher density. The effects of maternal care [...]
Linda Wilbrecht reviews Wildhood: The Epic Journey from Adolescence to Adulthood in Humans and Other Animals by Barbara Natterson-Horowitz and Kathryn Bowers (Scribner, 2019) in Science Magazine. An enduring story plot finds a youth suddenly alone in the world, struggling to find shelter from the elements, safety from predators, food, and new friends. These struggles usually involve some tough lessons but ultimately lead to knowledge, a new identity, self-reliance, and maybe even love. In Wildhood, this theme comes to exhilarating life as evolutionary biologist Barbara Natterson-Horowitz and science writer Kathryn Bowers describe the challenges faced by adolescent animals. Linda Wilbrecht, Coming of Age in the Animal Kingdom, reviewing Barbara Natterson-Horowitz and Kathryn Bowers, Wildhood: The Epic Journey from Adolescence [...]
Imaging striatal dopamine release using a nongenetically encoded near infrared fluorescent catecholamine nanosensor
Neuromodulation plays a critical role in brain function in both health and disease, and new tools that capture neuromodulation with high spatial and temporal resolution are needed. Here, we introduce a synthetic catecholamine nanosensor with fluorescent emission in the near infrared range (1000–1300 nm), near infrared catecholamine nanosensor (nIRCat). We demonstrate that nIRCats can be used to measure electrically and optogenetically evoked dopamine release in brain tissue, revealing hotspots with a median size of 2 µm. We also demonstrated that nIRCats are compatible with dopamine pharmacology and show D2 autoreceptor modulation of evoked dopamine release, which varied as a function of initial release magnitude at different hotspots. Together, our data demonstrate that nIRCats and other nanosensors of this class can [...]
The Tourette Association of America has awarded its Young Investigator Award to Kristen Delevich for her research project, Studying the Influence of Hormones on the Brain. This work seeks to understand the influence of puberty on brain circuits involved in behavioral control, in an effort to elucidate why Tourette symptoms typically change during adolescence. Congratulations, Dr. Delevich!
We just published our first collaborative paper with the Landry lab in Science Advances. Beyene et al. shows that new nIRCats enable detection of dopamine release with high spatial resolution and are compatible with dopamine receptor pharmacology. There is brief coverage in Nature and a link to the paper is here.