### Experimental design: Enhance human visual and auditory acuity and response speed through gene editing #### **1. Research background and objectives** -**Background**: Visual and auditory acuity and response speed are regulated by genes (such as photosensitive protein expression, cochlear hair cell function, nerve conduction efficiency). Gene editing techniques (such as CRISPR-Cas9 and base editing) can target and regulate related genes. -**Goal**: To enhance human sensory abilities through genetic modification, while ensuring safety and reversibility. --- #### **2. Target genes and mechanisms** -**Visual enhancement**： -**Gene target**： -**OPN1SW/OPN1MW**(cone cytochrome gene): Optimize spectral sensitivity and expand the visible range. -**CNGA3**: Enhance the efficiency of optical signal conduction. -**Introduce animal genes**: such as squid's opsin (S-opsin), to improve visual acuity in low-light environments. -**Mechanism**: Increase the density of cone/rod cells and optimize the signal transmission speed of retinal ganglion cells. -**Enhanced hearing**： -**Gene target**： -**TMC1**: Regulates the mechanical conduction channels of hair cells in the cochlea to improve sound sensitivity. -**GJB2**: Enhance the connection between cochlear cells and reduce signal loss. -**Introduction of high-frequency auditory genes**: Such as the Prestin protein gene of bats, it expands the frequency range of perceptible sound waves (>20kHz). -**Mechanism**: Repair or enhance the ability of hair cells to regenerate and reduce noise damage. -**Enhanced response speed**： -**Gene target**： -**BDNF**(Brain-derived neurotrophic factor): Promotes neuronal synaptic plasticity. -**SCN9A**: Optimize voltage-gated sodium ion channels to accelerate nerve signal transmission. -**Introduction of rapid response genes**: For example, motor neuron regulatory genes in predatory animals (such as Parvalbumin in cheetahs). --- #### **3. Experimental steps** **Stage 1: In vitro cell model verification** 1. **Cell selection**： -Vision: Human retinal organoids (cultured from induced pluripotent stem cells iPSCs). -Hearing: Cochlear implant hair cell model. -Nerves: Human neuronal cell lines (such as SH-SY5Y). 2. **Gene editing**： -Use CRISPR-Cas9 or Prime Editor for gene knock-in/knock-out. -Delivery tool: adeno-associated virus (AAV) or lipid nano particles (LNP). 3. **Test indicators**： -Vision: Opsin expression (flow cytometry), photoreaction sensitivity (calcium imaging). -Hearing: The intensity of the mechanical and electrical conduction current of hair cells (patch clamp technology). -Nerves: the speed at which the action potential propagates (microelectrode array). **Stage 2: Animal model verification** 1. **Model selection**： -Vision: Gene-edited mice (such as knocking in squid S-opsin). -Hearing: Transgenic rats carrying the human TMC1 gene. -Reaction speed: macaques (test complex behavioral responses). 2. **Functional test**： -Vision: water maze test (spatial resolution), light threshold behavior experiment. -Hearing: Determination of the threshold value of auditory brainstem response (ABR). -Reaction speed: avoidance reflex experiment, delay test for decision-making tasks. 3. **Safety assessment**： -Whole genome sequencing (off-target effect), long-term pathological observation. **Phase 3: Human clinical trial** 1. **Subject selection**： -Volunteer groups: patients with congenital sensory defects (such as color blindness and hearing loss) and healthy control groups. -Ethical review: Passed the IRB (Institutional Review Committee) and the Gene Therapy Ethics Committee. 2. **Delivery method**： -Local injection (sub-retinal injection or intracranial cochlear administration) or systemic delivery (for the nervous system). 3. **Monitoring and evaluation**： -Short-term: sensory acuity test (Snellen vision meter, pure tone hearing test), electroencephalography (EEG) reaction time. -Long-term: immune response, carcinogenic risk, germ cell editing exclusion. --- #### **4. Risk and ethical control** -**Risk**： -Off-target effects lead to unpredictable mutations. -Sensory allergies (such as reduced light/sound tolerance). -The immune system attacks the edited cells. -**Ethical measures**： -Strictly restricted to somatic cell editing (non-germ cells). -The informed consent process clarifies the experimental risks and exit mechanisms. -Data is transparent and subject to third-party supervision. --- #### **5. Expected results** -**Scientific value**: Reveal the functional network of sensory-related genes and promote the development of neuroengineering. -**Application scenarios**: Assisting patients with sensory impairments, special occupations (