=<font color="blue">'''This Week -
29 October 2021 (9:30 a.m., via Zoom)'''</font>= |+|
=<font color="blue">'''This Week - 2021 (9:30 a.m., via Zoom)'''</font>=
| || |
|−|<u>Speaker:</u> '''Megha Sehgal''' | |
| || |
|−|<u>Title: </u> ''' “ Branch-specific dendritic plasticity in retrosplenial cortex integrates contextual memories across time. ” ''' | |
| || |
|−|<u>Abstract:</u> Events occurring close in time are often linked in memory, providing an episodic timeline and a framework for those memories. Recent studies suggest that memories acquired close in time are encoded by overlapping neuronal ensembles, and that this overlap is necessary for memory linking. Transient increases in neuronal excitability drive this ensemble overlap, but whether dendritic plasticity plays a role in linking memories is unknown. Here, we show that contextual memory linking is not only dependent on ensemble overlap in the retrosplenial cortex (RSC), but also on RSC branch-specific dendritic allocation mechanisms. Using longitudinal two-photon calcium imaging of RSC dendrites, we show that the same dendritic segments are preferentially activated by two linked (but not independent) contextual memories, and that spine clusters added after each of two linked (but not independent) contextual memories are allocated to the same dendritic segments. Importantly, with a novel optogenetic tool selectively targeted to activated dendritic segments following learning, we show that reactivation of dendrites tagged during the first context exploration is sufficient to link two contextual memories. These results demonstrate a causal role for dendritic mechanisms in memory linking and reveal a novel set of rules that govern how linked and independent memories are allocated to dendritic compartments. | |
| || |
| || |
Revision as of 00:10, 3 November 2021
This Week - 05 November 2021 (9:30 a.m., via Zoom)
Speaker: Federico Calegari
Title: “ Making Brains with More Neurons: From the Womb to the Grave ”
Abstract: My group has found that the length of the G1 phase of the cell cycle influences the fate of somatic stem cells. This allowed us to promote the expansion of neural stem cells during development  and adulthood  to ultimately increase the number of neurons generated in the mammalian brain. This finding was important to reveal the contribution of specific progenitor subtypes in the evolutionary expansion and gyrification of the mammalian cortex  as well as the role of adult neurogenesis in promoting sensory discrimination  and cognitive performance over the course of life . Our next ambition is to understand how tuning the number of neurons in specific brain areas can promote specific brain functions and gain insights into the cellular basis of cognition.
The Integrative Center for Learning and Memory (ICLM) is a multidisciplinary center of UCLA labs devoted to understanding the neural basis of learning and memory and its disorders. This will require a unified approach across different levels of analysis, including;
1. Elucidating the molecular cellular and systems mechanisms that allow neurons and synapses to undergo the long-term changes that ultimately correspond to 'neural memories'.
2. Understanding how functional dynamics and computations emerge from complex circuits of neurons, and how plasticity governs these processes.
3. Describing the neural systems in which different forms of learning and memory take place, and how these systems interact to ultimately generate behavior and cognition.
History of ICLM
The Integrative Center for Learning and Memory formally LMP started in its current form in 1998, and has served as a platform for many interactions and collaborations within UCLA. A key event organized by the group is the weekly ICLM Journal Club. For more than 10 years, graduate students, postdocs, principal investigators, and invited speakers have presented on topics ranging from the molecular mechanisms of synaptic plasticity, through computational models of learning, to behavior and cognition. Dean Buonomano oversees the ICLM journal club with help of student/post doctoral organizers. For other events organized by ICLM go to http://www.iclm.ucla.edu/Events.html.
Megha Sehgal (Silva Lab) & Giselle Fernandes (Silva Lab).
Please email us at firstname.lastname@example.org if you would like to get regular updates regarding our journal club and weekly reminders.
Current Faculty Advisor:
i) Anna Matynia(Aug 2004 - Jun 2008) (Silva Lab)
ii) Robert Brown (Aug 2008 - Jun 2009) (Balleine Lab)
iii) Balaji Jayaprakash (Aug 2008 - Nov 2011) (Silva Lab)
iv) Justin Shobe & Thomas Rogerson (Dec 2011 - June 2013) (Silva Lab)
v) Walt Babiec (O'Dell Lab) (2013-2014)
vi) Walt Babiec (O'Dell Lab) & Helen Motanis (Buonomano Lab) (2014-2017)
vii) Helen Motanis (Buonomano Lab) & Shonali Dhingra (Mehta Lab) (2017-2018)
viii) Shonali Dhingra (Mehta Lab) (2018-2020)
Consult the User's Guide for information on using the wiki software.