What type of mechanoreceptor (mechanical sensory receptor) detects deep vibration?

Pacinian Corpuscles Detect Deep Vibration

Pacinian corpuscles are the mechanoreceptors primarily responsible for detecting deep vibration in the body. 1, 2, 3

Characteristics of Pacinian Corpuscles

Pacinian corpuscles have several distinctive features that make them uniquely suited for detecting deep vibration:

• Located deep within the dermis of the skin 4
• Specialized for detecting high-frequency vibrations (20-1000 Hz) 2
• Rapidly adapting mechanoreceptors that respond to transient touch and vibration 1, 3
• Have a large receptive field compared to other mechanoreceptors 4

Anatomical Structure

The Pacinian corpuscle has a complex structure that contributes to its specialized function:

• Onion-like structure with multiple concentric layers (lamellae) surrounding a central nerve fiber 2
• Composed of:
  • An inner core containing the afferent nerve terminal surrounded by lamellar Schwann cells (LSCs) 1, 3
  • An outer core consisting of multiple layers of lamellae with interlamellar fluid 2, 5
  • Total diameter of approximately 250 μm 4

Functional Mechanism

Recent research has revised our understanding of how Pacinian corpuscles function:

• Inner Core Role: Contrary to previous beliefs, the inner core (not the outer core) is primarily responsible for the rapid adaptation and frequency tuning of the Pacinian corpuscle 1, 3
• Mechanosensitivity: The lamellar Schwann cells in the inner core act as additional touch sensing structures that potentiate the mechanosensitivity of the afferent terminal 3
• Signal Amplification: The structure amplifies oscillatory strains within its target frequency band by a factor of 8-12 from the surface to the neurite 2
• Frequency Response: The corpuscle functions as a band-pass filter, with peak sensitivity to vibrations between 200-300 Hz 2, 5

Comparison with Other Mechanoreceptors

Pacinian corpuscles differ from other mechanoreceptors in several ways:

• Depth: Located deeper in the dermis compared to other mechanoreceptors 4
• Adaptation Rate: Rapidly adapting (unlike slowly adapting mechanoreceptors like Merkel cells) 1, 3
• Frequency Sensitivity: Specialized for high-frequency vibrations, unlike:
  • Meissner corpuscles (low-frequency vibration, light touch)
  • Merkel cells (pressure, texture)
  • Ruffini endings (skin stretch)

Clinical Significance

Understanding the role of Pacinian corpuscles has important clinical implications:

• Their deep location and large receptive field make them ideal for detecting vibrations transmitted through tissues 4
• Alterations in their structure due to aging or disease can affect frequency response and sensitivity to vibration 5
• Their function contributes to our ability to detect environmental vibrations, tool use, and tactile discrimination

Recent research has shown that the inner core's structure and function are more critical than previously thought, with the lamellar Schwann cells playing an active role in mechanosensation rather than merely supporting the nerve terminal 1, 3.