Search

Dopamine (DA)'s relationship with addiction is complex, and the related pathways in the mesocorticolimbic system are used to deliver DA, regulating both behavioral and perceptual actions. Specifically, the mesolimbic pathway connecting the ventral tegmental area (VTA) and the nucleus accumbens (NAc) is crucial in regulating memory, emotion, motivation, and behavior due to its responsibility to modulate dopamine. To better investigate the relationship between DA and addiction, more advanced mapping methods are necessary to monitor its production and propagation accurately and efficiently. In this study, we incorporate dLight1.2 adeno-associated virus (AAV) into our latest CMOS (complementary metal-oxide semiconductor) imaging platform to investigate the effects of two pharmacological substances, morphine and cocaine, in the NAc using adult mice. By implanting our self-fabricated CMOS imaging device into the deep brain, fluorescence imaging of the NAc using the dLight1.2 AAV allows for the visualization of DA molecules delivered from the VTA in real time. Our results suggest that changes in extracellular DA can be observed with this adapted system, showing potential for new applications and methods for approaching addiction studies. Additionally, we can identify the unique characteristic trend of DA release for both morphine and cocaine, further validating the underlying biochemical mechanisms used to modulate dopaminergic activation. [ABSTRACT FROM AUTHOR]

In this paper, we propose and demonstrate an implantable CMOS image sensor with self-resetting pixels. The self-resetting function is implemented using a four-transistor Schmitt trigger inverter. The pixel has no counter for the number of self-resets, because the application does not require radiometric (linear) response. The pixel is fabricated using the 0.35- \mu \textm 2-poly 4-metal standard CMOS technology, which results in the pixel size of 15~\mu \text m \times 15 ~\mu \textm and a fill factor of 31%. The effective peak signal-to-noise ratio is >59 dB. An image sensor prototype comprising a $60\times 134$ pixel array is designed, and an implantable device is fabricated. As an example imaging experiment, we demonstrate blood-flow imaging of a rat-brain surface using the sensor. Intensity-change images are successfully obtained from the self-resetting pixel outputs with the image processing. [ABSTRACT FROM AUTHOR]