What is two-photon microscopy

Two-photon microscopy, also known as two-photon excitation (2PE) microscopy, is a fluorescence imaging technique that allows for the observation of living tissues up to a depth of about one millimeter. In the two-photon excitation model, a molecule simultaneously absorbs two photons whose individual energy is only half of the energy needed to excite that molecule, and then releases the energy to a fluorescence photon. Two-photon microscopy (TPM) generally uses a near infrared excitation wavelength laser that reduces the tissue autofluorescence and optical scattering. It offers a powerful tool for observing the intricate processes within living organisms, especially for studying the dynamics of neurons, neural circuits, and other cellular interactions in deep tissues. 



  • Deeper tissue penetration
  • Reduced photodamage
  • High spatial resolution




What is miniature two-photon microscopy

An important goal of neuroscientists is to establish a connection between changes in the structure and function of neuronal circuits and changes in behavior. It is therefore crucial to study these phenomena in intact, behaving animals. By miniaturizing two-photon excitation (2PE) microscopes into devices small and light enough to be mounted on the heads of small animals, such as mice, it becomes possible to perform real-time, in vivo imaging of neuronal and cellular activities in the brain of an animal engaging in natural behaviors.

The miniature two-photon microscope from Transcend Vivoscope is so compact and lightweight that it can be affixed to a mouse's head without impeding its natural movements. This technology enables the observation of dynamic changes in neural synapses, neurons, and neural networks under various natural behavioral conditions, such as foraging, jumping, fighting, playing, and sleeping, as well as during the stages before, during, and after learning.



What’s so special about miniature two-photon microscopy

Sub-cellular resolution Single-spike resolution 1000+ neurons
Cell type-specific Free-behaving animal imaging Longitudinal study of the same population of cells



 Dendritic spines




Applications in neuroscience


Neural basis of cognition
  • Neural circuits for sensory cognition
  • Neural basis of learning and memory
  • Emotional information, sleep, and wakefulness
  • Brain development and neuron regeneration
  • Non-primate self-awareness
  • Neural mechanisms of social behavior
Mechanisms of brain diseases
  • Autism
  • Depression
  • Epilepsy
  • Parkinson's disease
  • Alzheimer's disease
  • Drug addiction
Drug development for brain diseases
  • Drug efficacy evaluation
  • Mechanisms of drug action
  • Drug target validation


  • Imaging subjects: Neurons, dendritic spines, microglia, astrocytes, neurovasculature, immune cells, mitochondria, etc. 
  • Research subjects: Brain, cerebellum, brainstem, spinal cord, liver, pancreatic islets
  • Neural circuit studies: Pain, itch, social interactions, decision-making, learning, memory, fear, movement, perception, emotions, etc.


And more……


Cardiovascular system, oncology, ophthalmology, immunology, endocrinology and metabolism, nephrology, pharmacology, dermatology, reproductive biology, hematology, developmental biology, dentistry, gastroenterology, hepatology, respiratory system, orthopedics