Afferent connections of the medial frontal cortex of the rat. A study using retrograde transport of fluorescent dyes. I. Thalamic afferents

https://doi.org/10.1016/0361-9230(90)90088-HGet rights and content

Abstract

The present study of the medial frontal cortex of the rat was undertaken with two objectives. First, to compare the pattern of afferent thalamic neurons for each of the three subdivisions of the medial frontal cortex: the medial precentral (PrCm), dorsal anterior cingulate (ACd) and prelimbic (PL) areas. Second, to provide a firmer basis for anatomical comparisons of cortical regions between rat and monkey. Focal injections of retrogradely transported fluorescent tracers, true blue and diamidino yellow, were placed in different regions of the medial frontal cortex, to reveal the organization of afferent thalamic neurons. The PL area can be readily distinguished from PrCm and ACd areas because it receives afferents from a large number of neurons from both the medial and the lateral parts of the mediodorsal nucleus (MD) whereas only a few neurons, from the lateral MD exclusively, project to PrCm and ACd areas. Moreover, the paratenial and the paraventricular thalamic nuclei project only to the PL area, and the central medial nucleus projects mostly to the PL area. The ventrolateral nucleus projects only to the dorsal part of the medial frontal cortex. The rhomboid, reuniens, ventromedial, intralaminar, posterior and laterodorsal nuclei project to the whole medial frontal cortex. On the basis of these findings, the pattern of thalamic afferents to the PL area was compared to the pattern of thalamic afferents to cingulate and retrosplenial cortices in rat. The conclusion is that the PL area has a pattern of thalamic afferents which is different not only from those of PrCm and ACd areas but also from those of cingulate and retrosplenial cortices. On the basis of its rich innervation from the mediodorsal nucleus, the prelimbic area could very likely be a part of the prefrontal cortex of rat.

References (41)

  • R.L. Reep et al.

    Afferent connections of medial precentral cortex in the rat

    Neurosci. Lett.

    (1984)
  • R.L. Reep et al.

    Efferent connections of the rostral portion of medial agranular cortex in rats

    Brain Res. Bull.

    (1987)
  • P.E. Sawchenko et al.

    A method for tracing biochemically defined pathways in the central nervous system using combined fluorescence retrograde transport and immunohistochemical techniques

    Brain Res.

    (1981)
  • K. Sripanidkulchai et al.

    Two rapid methods of counterstaining fluorescent dye tracer containing sections without reducing the fluorescence

    Brain Res.

    (1986)
  • L.W. Swanson

    A direct projection from Ammon's horn to prefrontal cortex in the rat

    Brain Res.

    (1981)
  • R.M. Beckstead

    An autoradiographic examination of corticocortical and subcortical projections of the mediodorsal-projection (prefrontal) cortex in the rat

    J. Comp. Neurol.

    (1979)
  • B. Berger

    Dopaminergic innervation of the frontal cerebral cortex. Evolutionary trends and functional implications

  • C.B.G. Campbell et al.

    The concept of homology and the evolution of the nervous system

    Brain Behav. Evol.

    (1970)
  • F. Condé et al.

    Origins of afferents to prefrontal cortex in the rat

    Soc. Neurosci. Abstr.

    (1988)
  • W.M. Cowan et al.

    The projection of the midline and intralaminar nuclei of the thalamus of the rabbit

    J. Neurol. Neurosurg. Psychiatry

    (1955)
  • Cited by (125)

    • Arc-Mediated Plasticity in the Paraventricular Thalamic Nucleus Promotes Habituation to Stress

      2022, Biological Psychiatry
      Citation Excerpt :

      We hypothesized that pPVT projections to the mPFC regulate habituation. The mPFC is the primary cortical target of the pPVT (23,26,48) and inhibits activity in key stress-related brain regions, including the amygdala (66,67) and HPA axis (45,46). pPVT-mPFC coherence was reduced in the delta, theta, and alpha frequency ranges during certain baseline and/or recovery bins in iAAV-Arc rats compared with iAAV-scramble control rats.

    • NR2B subunit in the prefrontal cortex: A double-edged sword for working memory function and psychiatric disorders

      2015, Neuroscience and Biobehavioral Reviews
      Citation Excerpt :

      In sensory cortices and hippocampus, this switch is strongly dependent on experience and neuronal activity (Yashiro and Philpot, 2008). These two factors do not appear to guide prefrontal development in a similar fashion as the PFC lacks direct thalamocortical innervation from the sensory thalamus with the exception of the mediodorsal nucleus of the thalamus (Conde et al., 1990; Ferguson and Gao, 2015; Giguere and Goldman-Rakic, 1988; Ray and Price, 1992). Although physiological properties and cognitive functions associated with the PFC are unique from other brain regions, we can utilize reports on the development of these other regions as a framework to guide our understanding of prefrontal development.

    • Visual attention: Linking prefrontal sources to neuronal and behavioral correlates

      2015, Progress in Neurobiology
      Citation Excerpt :

      Nonetheless, advocates for rodent-primate frontal homology have argued that since any single feature uniquely defining primate dlPFC is tenuous, a more informative way to define primate PFC for evaluating rodent-primate homology is in the relative strengths of its connections with multiple cortical and sub-cortical structures (Uylings and van Eden, 1990). In this vein, it has been argued that rodent Fr2 and ACd are homologous with primate dlPFC (and/or the FEF specifically) because as in the primate, rodent Fr2 and ACd exhibit relatively stronger reciprocal connections with the mediodorsal nuclei than with other thalamic nuclei, such as the ventrolateral or ventromedial nuclei (Uylings et al., 2003, but see Condé et al., 1990). Given this controversy about whether certain rodent frontal structures are more appropriately designated as homologous with primate PFC or primate PMC, it is interesting to consider the characteristics of the primate FEF (the most posterior extent of dlPFC) and its potential rodent homologue.

    • Limbic circuitry of the midline thalamus

      2015, Neuroscience and Biobehavioral Reviews
    View all citing articles on Scopus
    View full text