Hypothalamus and Thalamus Pathways

Hypothalamus Connections

• Humoral, Arteries → Hypothalamus
• Hippocampus (Fornix) → Mammillary Nuclei
• Amygdala (Stria Terminalis, Fugo Amygdala-Ventral Bundle) → Nuclei Chiasmatic and Tuberal
• Septal Nuclei (Medial Telencephalic Beam Lateral) ↔ Hypothalamus
• Brain Stem (Dorsal Longitudinal Fasciculus) → Hypothalamus

Hypothalamic Pathways

• Medial Forebrain Bundle
• Posterior Longitudinal Fasciculus
• Mammillothalamic Fasciculus
• Mammillomesencephalic Fasciculus (Tract of Gudden)
• Stria Terminalis
• Hypothalamohypophyseal Tract
• Descending Hypothalamic Fasciculus
• Hypothalamothalamocortical Fasciculus

Thalamus Nuclei and Pathways

Arquithalamus Nuclei

• Lateral Reticular Substance: Thalamic Reticular Nucleus (Gated Area of Arnold) (responsible for modulating dorsal thalamus)
• Inferior Reticular Substance: Equivocal Zone (projects subcortical vegetative information)
• Intralaminar Reticular Substance: Centromedian and Parafascicular Nuclei (modulation of putamen and caudate)
• Paracentral Nucleus: related to wake-sleep
• Centrolateral Nucleus: sleep-wake and respiratory centers
• Submedial Nucleus: related to nucleus solitarius (bone plate I?)
• Medial Reticular Substance / Juxtaependymal:
  • Nucleus of the Gray Commissure or Reuniens: sex hormones and reproductive instincts
  • Paraventricular Thalamic Nucleus: presoceptive sensation
  • Paratenial Nucleus: regulation of visceral function
  • Rhomboid Nucleus: related to respiratory and cardiovascular events

Paleothalamus Nuclei

• Lateral Geniculate Nucleus: visual analysis
  • Retina (Retinohypothalamic Pathway) →
  • Superior Colliculus →
  • → Pulvinar
  • → Area 17 (Radiations of Gratiolet)
  • → Areas 18, 19, 39, 40 (Primary Thalamocortical Radiations)
• Medial Geniculate Nucleus: auditory analysis
  • Vestibular Nuclei (Lateral Lemniscus?) →
  • Medial Geniculate (Probst's Angle?) →
  • → Posterior Dorsal Nucleus
  • → Areas 39, 40, 41 (Pfeifer's Radiations?)
• Ventral Posterior Nucleus: protopathic and epicritic sensation
  • Spinal Cord and Brainstem →
  • Trigeminal Nuclei →
  • Gustatory Information →
  • Vestibular Information →
  • → Lateral Dorsal Nucleus
  • → Areas 1, 2, 3
• Ventral Lateral Nucleus: unconscious proprioception
  • Cerebellum →
  • Interstitial Nucleus of Cajal →
  • → Ventral Anterior Nucleus
  • → Striatum
  • → Areas 4, 6

Neothalamus Nuclei

• Pulvinar: Visual Association
  • Lateral Geniculate Nucleus →
  • Auditory Radiations →
  • → Parietal, Temporal, Occipital Association Cortex
• Dorsal Posterior Nucleus: Auditory Association
  • Medial Geniculate Nucleus →
  • → Parietal Association Cortex
• Dorsal Lateral Nucleus: Tactile Association
  • Ventral Posterior Nucleus →
  • → Cingulate and Marginal Cortex