Artificial Intelligence Biological Sensors Cognitive Neuroscience Cognitive Science

Artificial Intelligence Biological Sensors Cognitive Neuroscience Cognitive Science Neuronal Pattern Analysis

Single Cell and Subcellular MALDI Mass Spectrometry for the Direct Assay of the Neuropeptides Physiological Saline MALDI Matrix Solution Cell Matrix Sample Plate Neuropeptides and hormones can be directly detected from biological samples ranging in size from femtoliter peptidergic vesicles to large invertebrate neurons. When combined with genetic information, the complete processing of prohormones into biologically active peptides can be measured in a single cell. Current work involves developing mass spectrometric imaging (to determine the precise locations of the peptides) and the ability to measure peptide release from single cells and brain slices.

Placenta vs. Brain – 3800 Placenta Array cy 3 cy 5

Center for Biomedical Computing • • Narendra Ahuja Bill Greenough William O'Brien Mark Band Steve Boppart Sariel Har-Peled Art Kramer • • • Harris Lewin Zhi-Pei Liang Lei Liu Greg Miller Jean Ponce Jim Zachary

Micro Patterned Neuronal Networks in Culture Recent Progress Robustness: Neurons Stay in Patterns for One Month Designability: Neurons Can Be Guided Over Electrodes on a Microelectrode Array Single fibers superimposed on electrodes Patterned fiber track superimposed on electrodes Bruce C. Wheeler, Member of the Neuronal Pattern Analysis and Biosensor Research Groups, Faculty in the Electrical and Computer Engineering Department

Micro Patterned Neuronal Networks in Culture Recent Progress Input/Output: Function: Are Neurons in Patterns More Active? Multiple Channel Electrical A. Patterned Networks Have Greater Activity Recordings Can be Without Patterns: 1% ± 3% active electrodes Obtained Routinely With Patterns: 16% 12% active electrodes B. Activity Increases with Cell Density % Active Electrodes 40 30 20 Patterned Neuron Cultures 10 0 100 200 300 400 500 Local Cell Density (per mm 2) Bruce C. Wheeler, Member of the Neuronal Pattern Analysis and Biosensor Research Groups, Faculty in the Electrical and Computer Engineering Department

Detection of weak signals in noisy spike trains B) Signal superimposed on noisy spike train A) Signal due to small prey C) Signal superimposed on regular afferent spike train Model of electric fish with electroreceptors distributed over its body. (A) The change in afferent firing activity due to a small prey. (B) the signal due to the prey superimposed on fluctuations due to spontaneous activity, in the case of a standard (binomial) model for afferent firing activity with the same firing rate as the afferent and (C) the signal superimposed on the actual afferent baseline activity. In contrast to (B), the afferent spike train exhibits long-term regularity (memory). This limits the fluctuations in baseline firing rate, making weak signals easier to detect. number of spikes in a 10 ms window with mean subtracted

Production of transgenic mice using cre-lox. P technology • Create cell-type specific knockout mice • Two lines of mice required: – cre mice which express cre in desired cells – lox. P mice with lox. P sites flanking the gene of interest cre mice lox. P mice

Creation of NR 1 lox. P mice

Characterization of NR 1 lox. P mice

Dendritic Development in Barrel Cortex

Dendritic Development in Barrel Cortex Chang and Greenough, 1988

Dendritic Development in Barrel Cortex CTL KO

Optical Coherence Tomography Fiber-Optic OCT Instrument High-Resolution OCT of Cell Mitosis & Migration rt ey g h v i Real-Time Endoscopic Imaging Non-Invasive Imaging of Developing Biology

Non-invasive optical imaging • New group of procedures for measuring the optical parameters of the cortex – Scattering and absorption of near-infrared (NIR) photons traveling through tissue • These parameters can be inferred by measuring: – The degree of light attenuation (intensity) – The degree of photon (phase) delay

Optical Methods Assessment of exposed tissue (UV and visible light) Intrinsic Contrast Absorption Fluorescence Light Scatter [Cytochrome. C-Oxidase] [NADH] Brain Cell Swelling during functional activity? [Oxy-Hb] [Deoxy-Hb] ‘Intrinsic Brain signals’? [oxy. Flaveoproteins] ‘Intrinsic Brain signals’? Contrast Agents Doppler Absorp- Fluores. Shift tion cence Blood Flow Blood Volume Blood Cell Velocity LDF Blood Flow Ion-Conc (e. g. Indicator (Ca, K, Mg) Dilution with Voltage Cardiogreen) Sensitive Dyes Microcirculation Assessment of deep tissue (Near infrared light) Contrast Agents Fluorescence Principally feasible, depending on tracer development? Intrinsic Contrast Absorp- Doppler Shift tion Blood Flow (Indicator dilution with Cardio green oxygen) NIRS Modified from A. Villringer Blood Flow Light Scatter Fluorescence Absorption Brain cell swelling during functional activity? FAST NIRS-Signals ? [Cytochrome. C-Oxidase] EROS [Oxy-Hb] [Deoxy-Hb] NIRS

Optical effects ¥“Slow” effects – develop over several seconds after stimulation – correspond to effects observed with f. MRI and PET – are presumably due to hemodynamic changes • “Fast” effects (EROS) – develop within the first 500 ms after stimulation – are most visible on the photon delay parameter – are presumably due to neuronal changes

Hb oxygenation in visual cortex Concentration changes / micro. M 0. 6 [oxy-Hb] 0. 4 0. 2 0. 0 -0. 2 -0. 4 [deoxy-Hb] -0. 6 0 5 10 15 20 25 30 35 40 45 50 55 60 Modified from A. Villringer Time / s

Comparison of PET and NIRS [oxy-Hb] vs. CBF [deoxy-Hb] vs. CBF -14 12 CBF (PET) 12 -20 oxy-Hb (NIRS) 30 -14 [total-Hb] vs. CBF -30 15 deoxy-Hb (NIRS) Modified from A. Villringer -14 -15 total-Hb (NIRS) 15

-1 Absorption Coefficient (cm ) NIR Absorption Spectra 0. 5 Water Hb 0. 4 0. 3 0. 2 0. 1 0. 0 600 Hb. O 2 700 800 900 1000 Wavelength (nm)

In-vitro scattering effects Scattering changes during an action potential voltage scattering Scattering changes during tetanic activation of a hippocampal slice

Phase delay measured at 5 k. Hz Synthesizer Delays (ps) EROS: Methods 1 2 3 Time (s) Stimulus Head surface LED Cerebral cortex PMT Signal Averaging Optic fiber Volume described by photons reaching fiber Delays (ps) 112 MHz 200 400 Time (ms) Average Evoked Response

Recording helmet

Neuro-Vascular Relationship • The hemodynamic (NIRS) effect is proportional to the size of the neuronal (EROS) effect integrated over time • This supports the use of hemodynamic brain imaging methods to quantify neuronal activity Gratton, Goodman-Wood, & Fabiani, HBM, in press

Upper-left visual stimulation f. MRI EROS pre-stimulus baseline 100 ms latency RH LH Gratton et al. , Neuro. Image, 1997 200 ms latency

Right Visual Field Stimulation Left Hemisphere Response Screen +