# Key Points from #hplusroadmap IRC Discussions

• Multiple tissue clearing and whole-brain imaging techniques were discussed, including SWITCH (allowing 20+ rounds of tissue labeling), CLARITY (transforms tissue into nanoporous hydrogel), CUBIC protocols, and cost-effective alternatives to expensive refractive index matching solutions like FocusClear.

• Kanzure proposed an innovative tissue clearing approach using gas or spray to liquify nanometer-thick tissue layers as an alternative to traditional blade-based methods, though noted current techniques use blades because samples are scanned after cutting.

• Several connectomics papers were shared, including one estimating whole mouse brain electron microscopic imaging costs at under $100 million, with potential optical approaches under $10 million, and a novel strategy called "Fluorescent In-Situ Sequencing of Barcoded Individual Neuronal Connections" (FISSEQ-BOINC).

• Participants discussed Robin Hanson's work on brain emulations, referencing Vitalik Buterin's tweet about "uncoordinated ecosystems of human-derived brain emulations" as a worthy topic of exploration.

• A DIY ultrasound scanner project was collaboratively developed, with participants tracking component requirements and specifications in a shared Google Docs spreadsheet.

• Multiple neuroscience papers were shared covering calcium regulation in memory performance, transcription factor Sp4's role in dendrite patterning, and chemical principles in tissue clearing for whole-body cell profiling.