Multisensory orientation behavior is disrupted by neonatal cortical ablation

Area of Science:

• Neuroscience
• Sensory Integration
• Developmental Plasticity

Background:

• The superior colliculus (SC) integrates visual and auditory information, enhancing neural responses and behaviors.
• This integration relies on inputs from the anterior ectosylvian sulcus (AES) and rostral lateral suprasylvian sulcus (rLS).

Purpose of the Study:

• To investigate the impact of neonatal ablation of AES and rLS on the development of multisensory enhancement in SC neurons and orientation behavior.
• To determine the necessity of these cortical inputs for normal multisensory orientation capabilities.

Main Methods:

• Neonatal ablation of AES and/or rLS in animal models.
• Behavioral testing at maturity to assess multisensory orientation to visual and auditory cues.
• Comparison of lesioned animals with control groups.

Main Results:

• Neonatal ablation of both AES and rLS precluded normal multisensory enhancements in orientation behavior.
• Animals with bilateral lesions could not use combined cues for contralesional target localization.
• Ipsilesional multisensory orientation remained intact.
• Removal of only one cortical area (AES or rLS) resulted in negligible long-term behavioral consequences.

Conclusions:

• The development of multisensory orientation behavior critically depends on early inputs from both AES and rLS.
• The neonatal brain exhibits significant plasticity, capable of compensating for the loss of a single cortical area.
• A substantial proportion of SC neurons must retain multisensory integration capabilities for behavioral benefits, which is compromised by the loss of both AES and rLS.