TABLE 1.

Summary of the phenotypical alterations observed in the retina of PD patients, Thy1-h[A30P]α-syn mice.

PD patients	References	Thy1-h[A30P]α -syn mice	TgM83 mice
α-syn in GCL, IPL, and INL	Beach et al., 2014; Ho et al., 2014; Bodis-Wollner et al., 2014a	α-syn in GCL, IPL, and INL	α-syn in ONL and INL
p-α-syn positive cell bodies and neurites in GCL	Beach et al., 2014; Ortuno-Lizaran et al., 2018a	p-α-syn positive cell bodies and neurites in GCL	p-α-syn labeling in outer and inner retina
			p-Tau (Thr231) in OPL and GCL
Thinning of NFL, GCL, IPL, and INL (OCT)	Shrier et al., 2012; Adam et al., 2013; Spund et al., 2013; Lee et al., 2014; Bodis-Wollner et al., 2014b; Matlach et al., 2018	Thinning of IPL (OCT)	Thinning of ONL (histology)
		Thickening of PL (OCT)
Decreased TH levels and TH-positive cell density in INL Decreased TH + plexus complexity	Nguyen-Legros, 1988; Harnois and Di Paolo, 1990; Chorostecki et al., 2015; Ortuño-Lizarán et al., 2020	Preserved TH-positive cell density in INL	Preserved TH levels in INL
		Preserved TH + plexus size in IPL
Decreased melanopsin-positive cell density in GCL and dendritic tree complexity	Ortuno-Lizaran et al., 2018b	Preserved melanopsin-positive cell density in GCL
Increased microglial reactivity (Iba-1)	Doorn et al., 2014; Ferreira and Romero-Ramos, 2018	No microglial reactivity (Iba-1)	Increased microglial reactivity (CD11b, CD68)
No macroglial reactivity (GFAP)	Mirza et al., 1999	No macroglial reactivity (GFAP)	Macroglial reactivity (GFAP)
RGC, bipolar and amacrine cell dysfunction (ERG):	Nightingale et al., 1986; Gottlob et al., 1987; Burguera et al., 1990; Ikeda et al., 1994; Peppe et al., 1992, 1995, 1998; Langheinrich et al., 2000; Sartucci et al., 2006; Garcia-Martin et al., 2014; Nowacka et al., 2015; Kashani et al., 2021	RGC and amacrine cell dysfunction (ERG):
− diminished responses of the photopic b-wave, scotopic oscillatory potentials and P50 component of the pattern ERG reversed by L-DOPA		− supernormal responses of the scotopic oscillatory potentials and pSTR (starting at 4 and 8 months, respectively)
− reversed by L-DOPA		− no overt response to L-DOPA

Retinal manifestations on the TgM83 mouse model were described in Mammadova et al. (2018). OCT, optical coherence tomography; NFL, nerve fiber layer; GCL, ganglion cell layer; IPL, inner plexiform layer; INL, inner nuclear layer; ONL, outer nuclear layer; OPL, outer plexiform layer; PL, photoreceptor layer; ERG, electroretinography; OPs, oscillatory potentials; pSTR, positive scotopic threshold response; and TH: tyrosine hydroxylase.