Andre F. de Sousa

It is finally out! Excited to share the main work from my postdoc in the Silva Lab at UCLA. We investigated how memories are organized in the brain (rdcu.be/ffPmX).

New paper from the lab. Using longitudinal ca imaging, activity-dependent tagging and optogenetics, we show that newly allocated fear engram neurons in amygdala undergo a brief period of coordinated “offline reverberation” immediately after learning. pnas.org/doi/10.1073/pn…

Excited to share our new paper with @ScottWilke5’s lab! 🎉 Led by @michaelgongwer, we uncover how rTMS drives therapeutic effects through cell type–specific plasticity in the prefrontal cortex. A big step toward understanding its mechanisms—take a look! sciencedirect.com/science/articl…

Ever notice how some moments feel heavier than they should? It may be because your brain is connecting them to older memories. New research from @deSousa_AndreF at @dgsomucla suggests fear grows when experiences get linked together over time. What we feel now is often shaped by what came before. nature.com/articles/s4159…

We’re excited to announce our next international, hands-on #Miniscope workshop covering everything from microscope design to experiments to analysis! Applications are now open for the 2026 Paris Miniscope Workshop (July 1–3, ESPCI). Apply by May 22: forms.gle/4CWh7MeMchLSjj…

@lavi_ayal @alcinojsilva Thanks Ayal! Hope all is well!

@deSousa_AndreF What a great thoughtful paper! Happy to see it finally out. Congratulations @deSousa_AndreF, @alcinojsilva and the team 👏.

It is finally out! Excited to share the main work from my postdoc in the Silva Lab at UCLA. We investigated how memories are organized in the brain (rdcu.be/ffPmX).

I am deeply grateful to my supervisor @alcinojsilva, collaborators @ladenardo , @BrainOfZedZed , all lab members (@almeidafilho, @YangShen, @Aless_Luchetti), and students who made this possible.

Take-home: The PFC controls whether new experiences are linked with prior memories by restricting which neurons are recruited for memory encoding. This mechanism provides a bridge between long-term memories and memory organization processes relevant for knowledge formation.

This pathway also regulates which neurons are recruited to encode new memories (independent of their pre-learning activity) revealing a new mechanism for controlling memory allocation based on prior experience.

Mechanistically, this control operates via a PFC → MEC → hippocampus circuit and involves modulation of ensemble overlap via neurogliaform inhibitory neurons in dCA1.

This reveals a top down control mechanism over memory organization in the hippocampus.

When mice encoded two different contexts 7 days apart: -> mPFC activity increased When we inhibited mPFC during encoding: -> Memories became linked -> Neuronal overlap increased in dCA1 -> Behavior was directly affected

Using a mouse model of memory linking, we show that the prefrontal cortex is recruited over time to control how memories are linked in the hippocampus.

Memories are not formed in isolation and are often integrated, or linked, with prior knowledge. Sometimes this is useful. Sometimes it can be dangerous. How does the brain decide which memories to connect and which to keep separate?

📣 #MCCS25 starts TOMORROW! Check out our poster session tomorrow & our symposium on Friday to hear from the best and brightest in molecular and cellular cognition. More information here: event.fourwaves.com/MCCS25/pages

Synaptic potentiation of engram cells is necessary and sufficient for context fear memory nature.com/articles/s4200…

@okaysteve Congrats Steve! Very exciting!

Haven't seen a Nature paper on synaptic plasticity in a while! This paper from Ulli Bayer's group shows that CaMKII's role in LTP induction is not enzymatic/phosphorylation of substrates like the AMPARs but a "structural" interaction with the NMDARs. nature.com/articles/s4158…

No direct projection from ACC to the hippocampus, after all.

🚨 neuro postdocs 🚨 Apps are open for year 2 of UCLA SYNCS -- a @UCLA_BRI funded extramural postdoc seminar series highlighting postdocs engaging impactful research AND community building. Please RT and apply now! tinyurl.com/SYNCS2023 See flyer or DM for details.