Human cortical organoids transplanted into the brain of newborn rats develop functional connectivity with host sensory circuits and shed light on neuronal dysfunction in Timothy syndrome. NBThighlight
O. The pH was titred to 7.3–7.4 with concentrated hydrochloric acid. The tissue was transferred to the laboratory within 30 min and coronal sections were made per the procedure described above.All animal procedures followed animal care guidelines approved by Stanford University’s APLAC. Rats were anaesthetized with 5% isoflurane for induction and 1–3% isoflurane during surgery. Animals were placed into a stereotactic frame and Buprenorphine Sustained-Release was administered subcutaneously.
. Fluorescence from each region of interest was extracted, converted to a dF/F trace, and then converted into a z-score.Rats were anaesthetized with 5% isoflurane for induction and 1–3% isoflurane during surgery. Animals were placed into a stereotactic frame and Buprenorphine SR and dexamethasone were administered subcutaneously. Whiskers contralateral to the t-hCO were trimmed to approximately 2 cm and threaded through mesh that was coupled to a piezo-electric actuator.
For optotagging experiments, a 200-µm diameter fibre-optic patch cord , coupled to a 473-nm laser , was connected to a 200-µm diameter optical fibre that was positioned above the craniotomy. Immediately before this, the power output from the patch cord was adjusted to 20 mW. Electrodes were lowered through the craniotomy into the target site using a manipulator and the craniotomy was filled with sterile saline. Ten pulses of 473-nm light were delivered at the start of the recording.
For analysis, spikes were sorted using Kilosort2 and were manually curated using Phy2 . Firing rates were computed using 200-ms bins, with a sliding window of 100 ms and converted into a z-score. A hidden Markov model with two states was used to label ‘on’ and ‘off’ states in the population activity. On states were considered to represent bursts, and off states were considered to represent inter-burst intervals.