Physiology and Biophysics

Seminars

Feb
21
Thu
2019
PBIO seminar series: Carlos Portera-Cailliau @ G-328 H.S.B.
Feb 21 @ 9:30 am – 10:30 am
Circuit Dysfunction Underlying Atypical Sensory Processing in Fragile X Syndrome Carlos Portera-Cailliau, M.D., Ph.D. Depts. of Neurology and Neurobiology David Geffen School of Medicine at UCLA Host: Andres Barria Abstract: To uncover the circuit-level alterations that underlie atypical sensory processing associated with autism, we have adopted a symptom-to-circuit approach in the Fmr1-/- mouse model of Fragile X syndrome (FXS).  For example, using a go/no-go behavior task and in vivo 2-photon calcium imaging, we find that impaired visual discrimination in Fmr1-/- mice correlates with marked deficits in orientation tuning of principal neurons, and a decrease in the activity of parvalbumin (PV) interneurons in primary visual cortex.  Restoring visually evoked activity in PV cells in Fmr1-/-mice with a chemogenetic (DREADD) strategy was sufficient to rescue their behavioral performance.  Strikingly, human subjects with FXS exhibit similar impairments in visual discrimination as Fmr1-/- mice.  These results suggest that manipulating inhibition may help sensory processing in FXS.
Mar
14
Thu
2019
PBIO seminar series: Robert Fettiplace @ G-328 H.S.B.
Mar 14 @ 9:30 am – 10:30 am
Robert Fettiplace, PhD Steenbock Professor of Neural and Behavioral Sciences Department of Neuroscience University of Wisconsin-Madison host: Peter Detwiler
Mar
21
Thu
2019
PBIO seminar series: Burns C. Blaxall, Ph.D. @ G-328 H.S.B.
Mar 21 @ 9:30 am – 10:30 am
seminar title: TBA Burns C.Blaxall, PhD, FAHA, FACC, FAPS
Director of Translational Science, Heart Institute Director, Center for Translational Fibrosis Research Co-Director, Heart Institute Clinical Research Core & Biorepository
Cincinnati Children’s Hospital Medical Center Professor, UC Department of Pediatrics   host: Chris Liu
Apr
23
Tue
2019
PBIO seminar series: Trevor Lamb @ G-328 H.S.B.
Apr 23 @ 9:30 am – 10:30 am
Trevor Lamb   host: Peter Detwiler
Apr
24
Wed
2019
2019 Hille Lecture – Bernardo Sabatini @ TBA
Apr 24 all-day
time: TBD location: TBD Bernardo Sabatini (Harvard Medical School)     host: Stan Froehner
May
16
Thu
2019
PBIO seminar series: Colleen Clancy @ G-328 H.S.B.
May 16 @ 9:30 am – 10:30 am
Colleen Clancy UC Davis   host: Sharona Gordon
May
23
Thu
2019
PBIO seminar series: Rachel Martin @ G-328 H.S.B.
May 23 @ 9:30 am – 10:30 am
What can we learn about protein solubility and aggregation from a cold fish?
Rachel Martin
Professor Departments of Chemistry and Molecular Biology & Biochemistry UC Irvine
host: Sharona Gordon
seminar abstract: The βγ-crystallin fold that is ubiquitous in the structural proteins of the vertebrate eye lens is an ancient structural motif found in diverse organisms from all three domains of life. In organisms without eyes, e.g. archaea, bacteria, tunicates, and sponges, βγ-crystallins serve as calcium-binding proteins.  In vertebrates, they are primarily found in the eye lens, where they play an important role in controlling the refractive index gradient of this specialized tissue.  The ubiquitous βγ-crystallins of the vertebrate lens are believed to have descended from an ancestral single-domain Ca2+-binding crystallin by a process that included gene duplication resulting in two copies of the double Greek key domain per chain, as well as selection for high refractive index. Because the lens has negligible protein turnover, the crystallins must remain stable and soluble for the lifetime of the organism despite their extremely high concentrations. In particular, we are interested in the resistance to phase separation of the cold-adapted crystallins of the Antarctic toothfish, Dissostichus mawsoni. The eye lens of D. mawsoni is evolutionarily adapted to function in the permanently sub-freezing waters of the Southern Ocean.  This is in contrast to temperate and tropical fishes, and endothermic mammals, the lenses of which undergo liquid-liquid phase separation at low temperatures.  Mammalian lenses phase separate at temperatures between 10 °C and 20 °C – well above the Antarctic’s sub-zero marine environment.  The ability of the toothfish lens to maintain transparency in this frigid environment is particularly remarkable given that fish lenses have a high concentration of constituent proteins ≥1000 mg * mL-1). Recent work in my group focuses on testing the hypothesis that γ-crystallin isoform heterogeneity coupled with cold selective evolutionary pressures contribute to the clarity of the toothfish lens.  We have measured the thermal stabilities and phase diagrams of seven key γ-crystallin lens proteins, and we are able to control the onset of liquid-liquid phase separation by introducing a small number of surface mutations. The implications of our findings with respect to the roles of frustration, ionic interactions, and protein flexibility liquid-liquid phase separation will be discussed.  
Jun
6
Thu
2019
2019 Crill Lecture – Leslie B. Vosshall @ TBA
Jun 6 – Jun 5 all-day
http://vosshall.rockefeller.edu/ host: Stan Froehner