Lauren Kreeger

How the brain tunes in Specialized cells that help us distinguish between sounds in a noisy environment rely on both activating and repressing signals to process inputs fully.

In a sea of noise, your brain’s ‘octopus cells’ choreograph a delicate dance of signals, some pushing sound forward, others holding it back. This balance lets you lock onto a single voice in the chaos.

We find that dendritic inhibition changes how excitation from the auditory nerve is integrated in the dendrites. Inhibition on dendrites changes temporal integration locally while still allowing the cell to maintain its incredible submillisecond coincidence detection computations in the soma.

By changing the electrical compartmentalization of octopus cell dendrites with ion channel blockers, we were able to unmask inhibition that is localized to octopus cell dendrites for the first time!

We then asked if they receive inhibition. It was previously assumed that these cells only get excitation from the nerve. It made sense at the time! The area where octopus cells can be found, conveniently called the octopus cell area (OCA), is seemingly devoid of inhibitory puncta.

We first asked, what type of inputs octopus cells receive from the ear? Using genetic labelling of auditory nerve fibers, we found that octopus cells predominantly get input from nerve fibers with low sound intensity thresholds, which is to say they encode quiet sounds well.

Octopus cells are extremophiles. Their electrical properties are specialized so they can integrate inputs with incredible precision (200µs time constants and 10MΩ input resistances… IYKYK). This makes them excellent detectors of coincident activity across the many tones that the ear can hear.

All mammals have a beautiful neuron in their brainstem called the octopus cell. I love that Kirsten Osen gave them this name in 1969: “As many of the cells have all their dendrites gathered on one side of their cell body, they often look like octopuses, and therefore I propose that name for them.”

Thrilled that our paper has been published in @elife.bsky.social
doi.org/10.7554/eLif...

We ask: how can a neuron integrate information across multiple time scales?

Twist: This neuron has extreme properties that helps it work ~300x times faster than neurons in the hippocampus

Summary 🧵to follow

@audreydrotos.bsky.social has it completely right. We need to continue to educate members of congress about the issues that are critical to their constituents. And if they don’t have legislative aides that focus on something as basic as healthcare and science— ask why it’s not a priority.

ATTN: Pennsylvania science folks! @laurenkreeger.bsky.social and I visited Senator McCormick (PA) yesterday and spoke to him about NIH cuts. He *did not know* there were active cuts to grants in part because he does not currently have a health care or science legislative aide to brief him. (1/2)

I had a great day in DC with @audreydrotos.bsky.social! First we talked with Sen. McCormick at the #KeystoneBreakfast and then met with a legislative aide for @fetterman.senate.gov. Great to speak with them about the future of biomedical research and the importance of the NIH.

Perfect way to start the new lab and the new year! Excited to talk about octopus cells with everyone

Check out our website www.med.upenn.edu/pennhearing/... and mark the dates for the spring semester EARS seminars:
1/14 Tania Barkat, Lauren Kreeger
2/11 Laura Getz, Josh McDermott
3/11 Professional Development Seminar
4/8 Trainee Seminar
5/13 Pierre Apostolides, Maria Chait
Please repost!