Publications2019-02-01T12:21:02+00:00

Pubmed: Wilbrecht L

Distentangling the systems contributing to changes in learning during adolescence

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 […]

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 […]

November 20th, 2019|Tags: , , , |

Coming of age in the animal kingdom

September 27th, 2019|Tags: |

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 […]

Neuroscience: Sex Hormones at Work in the Neocortex

Sex hormones have easy access to the brain and their receptors are expressed by cortical neurons. Until recently, little was known about what impact, if any, they have on cortical processing. New data reveal that estradiol potently alters inhibitory neurotransmission in the neocortex.

Kristen Delevich, David Piekarski, Linda Wilbrecht, Neuroscience: Sex Hormones at Work in the Neocortex,
29(4) Current Biology R122–R125 (2019) https://doi.org/10.1016/j.cub.2019.01.013, http://www.sciencedirect.com/science/article/pii/S0960982219300156

February 22nd, 2019|Tags: , , |

Adolescence and “Late Blooming” Synapses of the Prefrontal Cortex

The maturation of the prefrontal cortex (PFC) during adolescence is thought to be important for cognitive and affective development and mental health risk. Whereas many summaries of adolescent development have focused on dendritic spine pruning and gray matter thinning in the PFC during adolescence, we highlight recent rodent data from our laboratory and others to call attention to continued synapse formation and plasticity in the adolescent period in specific cell types and circuits. In particular, we highlight changes in inhibitory neurotransmission onto intratelencephalic (IT-type) projecting cortical neurons and late expansion of connectivity between the amygdala and PFC and the ventral tegmental […]

February 1st, 2019|Tags: , , |

Mice engineered to mimic a common Val66Met polymorphism in the BDNF gene show greater sensitivity to reversal in environmental contingencies

A common human polymorphism in the gene that encodes brain derived neurotrophic factor (BDNF), Val66Met, is considered a marker of vulnerability for mental health issues and has been associated with cognitive impairment. An alternate framework has been proposed in which “risk alleles” are reinterpreted as “plasticity alleles” that confer vulnerability in adverse environments and positive effects in neutral or positive environments (Belsky et al., 2009). These frameworks produce divergent predictions for tests of learning and cognitive flexibility. Here, we examined multiple aspects of learning and cognitive flexibility in a relatively new BDNF Val66Met mouse model (BDNF Val68Met, Warnault et al., 2016), […]

December 1st, 2018|Tags: , , , , |

Imaging Striatal Dopamine Release Using a Non-Genetically Encoded Near-Infrared Fluorescent Catecholamine Nanosensor

Neuromodulation plays a critical role in brain function in both health and disease. New optical tools, and their validation in biological tissues, are needed that can image neuromodulation with high spatial and temporal resolution, which will add an important new dimension of information to neuroscience research. Here, we demonstrate the use of a catecholamine nanosensor with fluorescent emission in the 1000-1300 nm near-infrared window to measure dopamine transmission in ex vivo brain slices. These near-infrared catecholamine nanosensors (nIRCats) represent a broader class of nanosensors that can be synthesized from non-covalent conjugation of single wall carbon nanotubes (SWNT) with single strand oligonucleotides. […]

Your Twelve-Year-Old’s Brain Chapter in Think Tank

Professor Wilbrecht’s essay, Your Twelve-Year-Old Isn’t Just Sprouting New Hair but Is Also Forming (and Being Formed by) New Neural Connections, appears in Think Tank: Forty Neuroscientists Explore the Biological Roots of Human Experience (David J. Linden, ed. 2018).

April 24th, 2018|Tags: |

Importance of investing in adolescence from a developmental science perspective

This review summarizes the case for investing in adolescence as a period of rapid growth, learning, adaptation, and formational neurobiological development. Adolescence is a dynamic maturational period during which young lives can pivot rapidly—in both negative and positive directions. Scientific progress in understanding adolescent development provides actionable insights into windows of opportunity during which policies can have a positive impact on developmental trajectories relating to health, education, and social and economic success. Given current global changes and challenges that affect adolescents, there is a compelling need to leverage these advances in developmental science to inform strategic investments in adolescent health.

Ronald E. […]

February 21st, 2018|Tags: , , , |